Updated 3:34 p.m. ET - President Barack Obama hailed the Senate's bipartisan immigration framework at a major speech on that topic this afternoon in Nevada, but threatened to send his own alternative legislation to Capitol Hill if Congress fails to act.

The president embraced of a statement of principles offered Monday by four Democratic and four Republican senators, which would strengthen border security and employment verification in exchange for a path to citizenship for undocumented immigrants in the United States.

"The good news is that -- for the first time in many years -- Republicans and Democrats seem ready to tackle this problem together," Obama said in his speech in Las Vegas, according to prepared excerpts.

Jason Reed / Reuters

President Barack Obama arrives in Las Vegas, Jan. 29. Obama arrived in Nevada to deliver remarks on immigration reform.

"And yesterday, a bipartisan group of senators announced their principles for comprehensive immigration reform, which are very much in line with the principles I've proposed and campaigned on for the last few years," the president also said. "At this moment, it looks like there's a genuine desire to get this done soon. And that's very encouraging."

But in a speech in Nevada -- a Southwestern state that has experienced a boom in its Hispanic population -- the president said he refused to allow comprehensive immigration reform "to get bogged down in an endless debate."

"It's important for us to realize that the foundation for bipartisan action is already in place," he said. If lawmakers fail to advance their own proposal, Obama said he would send legislation to Congress based on his own principles "and insist that they vote on it right away."

He said at the top of his speech: "I'm here because the time has come for common-sense, comprehensive immigration reform."

The president used Tuesday's speech in Nevada to outline many of those principles, which rest on four pillars: strengthening border security, cracking down on employers who hire undocumented workers, streamlining legal immigration and -- most importantly -- offering undocumented workers an earned path to citizenship. 

Those pillars mostly resemble the bipartisan Senate framework unveiled on Monday by lawmakers, which has prompted hopes that Congress would finally be able to advance a comprehensive immigration reform law, a priority that eluded Obama during his first term, and President George W. Bush before him.

The primary sticking point in those fights has been the pathway to citizenship, which conservatives deride as "amnesty" for those who have broken the law. Already, some prominent conservatives have expressed their skepticism of the Senate framework for exactly that reason.

"Yes, they broke the rules," Obama said of those undocumented immigrants. "They crossed the border illegally. Maybe they overstayed their visas. But these 11 million men and women are now here."

Republicans in particular had been closely watching Obama's actions for cues as to how the administration might handle immigration, and the emerging Senate deal. Republican lawmakers have openly worried that the president might stake out stark positions and oppose some of the enforcement measures included in the Senate framework, namely the trigger that would only allow a pathway to citizenship once the border enforcement mechanisms had been verified. 

"There are a lot of ideas about how best to fix our broken immigration system," said Brendan Buck, a spokesman for House Speaker John Boehner, R-Ohio. "Any solution should be a bipartisan one, and we hope the President is careful not to drag the debate to the left and ultimately disrupt the difficult work that is ahead in the House and Senate."

But Florida Sen. Marco Rubio, a rock star to conservatives who's seen as eyeing a run for the GOP presidential nomination in 2016, has taken an active lead in selling this proposal to the right. Rubio has appeared in conservative media to both discourage Obama from opposing enforcement provisions, but also talk up the proposal as the best chance at compromise for Republicans.

"If, in fact, this bill does not have real triggers in there -- in essence, if there's not language in this bill that guarantees that nothing else happens unless these enforcement mechanisms are in place -- then I won't support it," Rubio, a member of the bipartisan gang of eight, told conservative radio host Rush Limbaugh on Tuesday. "But the principles clearly call for that."

But the president generally spoke in broad terms, and did not draw any bright lines as it relates to the Senate proposal. 

"I believe we are finally at a moment where comprehensive immigration reform is finally within our grasp," he said.

RENO, Nev. – Republican vice presidential nominee Paul Ryan kicked off what he called a "barnburner" of a final day on the campaign trail, courting voters out west in Nevada.

“Are you gonna help us win this thing Nevada? We're doing a barnburner today. We are crisscrossing the country Mitt and I are because we are asking you to work with us, to stand with us to get our country back on the right track,” Ryan told the crowd inside a hangar at the Reno Tahoe International Airport.

Ryan is holding five campaign rallies in four time zones Monday while Romney is holding five events along the East Coast.

Monday’s stop in Reno marks the GOP VP nominee’s sixth event in the Silver State and, with national polls tight between Romney and President Barack Obama, Ryan said Tuesday’s election could come down to Nevada.

"Look, a handful of states are gonna figure this out. So many Americans are looking to you, right here in Reno, right here in Nevada, and a handful of states like my own. And they're looking to you to make sure that you cast your vote for actual real change. That you cast your vote to get us off this dangerous path that we are on and back on the right track," he said to the roughly 1,000 people in attendance.

Ryan was joined by his wife and three children in addition to Romney’s son, Craig, at this first stop of the day less than 24 hours before polls open.

“Nevada we are counting on you. We know you can do this. We are in this together and let's just run through the tape, let's leave it all on the field,” Ryan asked supporters before heading off to Colorado for his next event.

RENO, NV -- Mitt Romney returned to Nevada for the second straight day on Wednesday, hoping to boost support in this critical Western battleground by personalizing his message to different slices of Silver State voters.

Romney again claimed his three debates versus President Barack Obama, the last of which was on Monday in Florida, claiming the post-debate momentum and seizing the mantle of being the candidate of "change."

"We’ve had four debates and he hasn’t been able to describe what his plan is to get this economy going. He hasn’t been able to defend it to the American people," Romney said of his debates with President Obama, as well as the VP debate. "I know he’s got a lot of discussion he’s trying to talk to people about it but you know you can boil what he’s saying down to four simple words: And that is more of the same. And we don’t want more of the same. We can’t afford four more years like the last four years."

Romney has hammered at that message at each of three campaign stops since the final debate Monday night, looking to convince voters his campaign has momentum and that the president's cause is fizzling.

Brian Snyder / Reuters

Republican presidential nominee Mitt Romney and vice-presidential nominee Paul Ryan talk on the tarmac at the airport in Denver, Colorado before parting ways to campaign separately October 24, 2012.

"The Obama campaign is slipping and shrinking," Romney told the 2,000-plus supporters gathered here today. "The president can't seem to find an agenda to help America's families."

The GOP nominee, who has sometimes struggled to connect personally with voters, today amended his stump speech to touch on how his plan would be better for Americans in specific demographic groups, using the issue of debt and deficits to appeal for support from young women by describing how debts run up by the president could cost them a chance at the American dream.

"Let me tell you how else this might affect, might affect your family, how this choice that you’re making will make a difference in your family. You might have a daughter graduating from college this spring. And she’s gonna come out and she’s gonna probably have 10 or $20,000 in student loans to pay back, and she’s going to be paying the interest on that for a long, long time," Romney said.

"But in addition to those loans, there’s something else that she has, about $50,000 per person for America in debt," Romney said of a hypothetical young woman who graduated from college with student loan debt. "And so when she gets her first paycheck and she sees the deductions for taxes, some of those taxes are going to pay for that debt, and for things she didn’t get, for things that our generation took upon ourselves. And she’s going to be paying for that all of her life. And so the American dream she had been told about by you, her parents, that American dream is going to be out of reach."

In Nevada, the state with the nation's worst unemployment rate, currently stuck at 11.8 percent, Romney did not linger more than usual on his five-point jobs plan, but promised the steps would "get America's economy just cooking again."

To win Nevada's six electoral votes, Romney advisers say the GOP candidate must overperform here in Washoe county, which broke for Obama by 12 points in 2008 but is traditionally more of a swing county. A strong performance there would be necessary to counteract the union-backed Democratic machine in Clark County, home to Las Vegas, and the state's largest population center.

Voters like Steve Wren, 50, a pastor at a church in Reno and a self-described "pro-life Democrat," could be key to Romney's success here. Wren joined his wife, who is supporting Romney, at today's event and told NBC News before the event began that he was still unsure if he would vote for the GOP nominee this time around, after reluctantly breaking from his lifelong support for Democrats to vote for Sen. John McCain in 2008.

"I think he made it clear with what he said. I think its pretty obvious that, well, its obvious to me, that I don't really like where we're going and so we sort of have one choice," Wren said after the rally, adding that he would most likely be voting for Romney after being pleasantly surprised by how "genuine and real" Romney seemed in person.

"I heard a lot of the stuff that I've always heard, so maybe it was just being here and seeing him in person but there was just something that seemed really passionate and genuine, so I was touched by that," Wren said. 

The economy remains the top issue for voters, and a new set of data released Friday paints a picture of an uneven economic recovery in a series of battleground states.

Of the nine states categorized as "battleground states" by NBC News, five had state unemployment rates below the national unemployment rate of 7.8 percent in September, according to preliminary estimates released Friday by the Bureau of Labor Statistics.

The other four states suffered from a higher-than-average jobless rates, the highest of which was in Nevada; the BLS said that 11.8 percent of Nevadans were unemployed through September, the highest unemployment rate of all 50 states. (One U.S. territory, Puerto Rico, had a higher jobless rate.)

Friday's news is the last series of state-level unemployement data voters will receive before Election Day. One last national jobs report is due Nov. 2, the Friday before voters head to the polls.

President Barack Obama and Republican nominee Mitt Romney have each made jobs the centerpiece of their respective campaigns. The president got a boost earlier this month when the BLS report showed the unemployment rate dropping below 8 percent for the first time in years, disarming Romney of one of his most potent cudgels versus the president.

But as each Obama and Romney travel the country over the next 18 days looking to secure the 270 electoral votes they need to win the White House, economic optimism might be brighter in some states and still dim in others.

The five states with unemployment rates below 7.8 percent included Iowa (5.2 percent), New Hampshire (5.7 percent), Ohio (7.0 percent), Virginia (5.9 percent) and Wisconsin (7.3 percent).

The four battleground states with unemployment rates above the national average are Colorado (8.0 percent), Florida (8.7 percent), Nevada and North Carolina (9.6 percent).

If, for purposes of speculation, Obama were to win the battleground states with jobless rates beneath 7.8 percent along with all of the other states considered more safely in his column, he would win the Electoral College, 288-250.

But politics, of course, are not that simple. For instance, the number of employees on nonfarm payrolls in Ohio actually decreased between August and September, though the unemployment rate dropped from 7.2 percent to 7 percent over the same period.

But as Obama argues that the economy is moving forward and Romney asserts that the recovery has not been sufficiently robust, it's helpful to remember how those arguments might sound different to voters in differing states.

Updated 5:04 p.m.: LAS VEGAS -- Vice President Joe Biden drew a rebuke from Republicans on Thursday after he referenced GOP vice presidential nominee Paul Ryan's policy manifesto, "Young Guns," by warning that "the bullets are aimed at you."

After Biden mentioned the book, which Ryan co-wrote with two other top House Republicans, a man in the crowd of about 500 at a Las Vegas union hall yelled out "they have guns with no bullets!" 

"Unfortunately, the bullets are aimed at you," Biden said, to mirth from the boisterous crowd.

The exchange prompted an immediate statement from Romney spokesman Brendan Buck, who decried the language as "over the top."

"Today's over-the-top rhetoric by Vice President Biden is disappointing, but not all that surprising," Buck wrote. "In the absence of a vision or a plan to move the country forward, the Vice President is left only with ugly political attacks beneath the dignity of the office he occupies."

No stranger to controversy, Biden faced heavy scrutiny in August for telling a heavily black audience in southern Virginia that Romney's Wall Street deregulation would "put y'all back in chains."

Ironically, Biden opened his remarks in Nevada by doing something he often does: joking about his propensity to veer off-script.

"The vice president’s exchange with an audience member today was clearly a reference to how the policies discussed in Paul Ryan’s book, 'Young Guns,' would devastate the middle class," said Amy Dudley, a campaign spokeswoman for the vice president. "Given that people don't assume that Paul Ryan is literally a gun, it probably makes sense not to assume that Joe Biden was speaking literally about bullets."

The Sin City stop was Biden's last campaign event of a 2-day western swing that focused heavily on women's issues and immigration.

In Las Vegas, Biden warned that a Romney presidency would likely erase the gains of advocates of abortion rights.

"After these debates, you have any doubt who they will likely appoint to the Supreme Court of the United States," Biden said. "How much chance do you think Roe v. Wade will survive after four years of a Romney Supreme Court?"

He also uncorked a new zinger, adapted from yesterday's full news cycle of Democrats labellng Romney's plans as "sketchy."

"Well folks, I don't think they were just sketchy," he declared. "I think they were etch-a-sketchy!"

Mitt Romney is fighting to earn a new look from voters with 30 days remaining until the election, as President Barack Obama looks to close the window on his Republican challenger. 

Romney, the Republican presidential nominee, has hopes of building momentum off of his strong debate performance this week, in which he generally outperformed Obama with energetic and crisp arguments.

But a top spokesman for the president vowed Sunday that Obama wouldn't allow Romney a repeat performance in their second showdown.

"It's not rocket science to believe the president was disappointed in the expectations he has for himself," former White House press secretary Robert Gibbs said on "Meet the Press" of Obama's debate performance, which was panned as lethargic and lacking in aggression.

Of the second debate, scheduled for Oct. 16, Gibbs said, "I think you're going to see a very engaged president that is ready and willing to call out whichever Mitt Romney shows up."

Romney "walked over" Obama in Denver, former House Speaker Newt Gingrich, one of Romney's erstwhile primary opponents, contended. But Gingrich also acknowledged that the GOP nominee had "changed" from the primary, when he vowed to cut taxes for individuals in all income brackets. (Romney said in Wednesday's debate that, in his reform plan, the wealthy wouldn't end up paying any less in taxes.)

Whether Romney has made up much ground versus Obama hasn't yet been fully reflected in polls conducted since the debate. The Republican hopeful entered the matchup trailing the president, and must make up ground — especially in battleground states like Ohio — if Romney is to have any hope of winning on Nov. 6.

"The real question to me, of this campaign, is, can the Romney campaign take this moment and run with it?" asked Mike Murphy, a longtime Republican consultant with ties to Romney.

Romney won the endorsement of a newspaper in one such swing state, Nevada, as the editors of the Las Vegas Review-Journal said Romney "has the principles and experience needed to put America back on the road to prosperity."

But Obama's case for re-election was bolstered Friday by a new jobs report that showed the unemployment rate at 7.8 percent in September, clearing the psychological barrier of 8 percent, above which the unemployment rate had sat for months. 

"I think it was a significant help to the president," Gingrich said of that report.

Obama's advantage over Romney was fueled partly by improving perceptions of the economy, which could be cemented by the new employment data. If nothing else, the president will have a new cudgel to wield against Romney in their next debate matchup. 

Both Romney and Obama will leave it to their running mates this week to carry the banner on Thursday, at the vice presidential debate. 

"I know Vice President Biden is anxious and ready to do this," Gibbs said of Biden's impending debate versus Wisconsin Rep. Paul Ryan, the Republican vice presidential nominee.

In the meanwhile, both the president and Romney aren't taking the weekend off; instead, they're both on the campaign trail this Sunday. Romney will hold a rally this afternoon in Florida, while Obama attends a "30 days to victory" fundraising concert tonight in Los Angeles.

LAS VEGAS -- It may have been the small, echoing gym filled with 2,700 yelling people, but at today’s campaign event, President Barack Obama felt more “fired up, ready to go” than he’s seemed in a while.

Today’s focus, like the two events yesterday, was education. But the president allowed himself to get a bit more expressive when talking about the importance of teachers.

Isaac Brekken / AP

President Barack Obama speaks during a campaign stop, Wednesday, Aug. 22, 2012, in North Las Vegas, Nev.

And while the actual content of the last two days' education-driven speeches hasn’t been incredibly different, the president’s tone seemed affected by the raucous crowd responses, including a sustained “four more years” chant to overpower a heckler who ended up being ejected from the event by Secret Service.

And this crowd also ended up drowning the president himself out as he finished up his speech, almost yelling: “We've got more veterans we've got to help. We've got more doors of opportunity we've got to open up to every single American. That's why I'm asking for a second term."

The president has spoken about his fifth grade teacher in the past, but bringing her up today allowed him to also put a personal spin on painting presumptive GOP presidential nominee Mitt Romney as extremist on the subject of education.

“The right teacher can change a child's life forever. Look, I know this from personal experience. When I was in fifth grade, I had a teacher named Mabel Hefty. That was her name. And she was a great teacher," Obama started into the story. "I had just come back from living a few years overseas with my mom and wasn't sure how I'd fit in. And she noticed that, Ms. Hefty. And she took me under her wing, and she made me feel like I had something to say, and that I had some talent."

"Gov. Romney says we've got enough teachers, we don't need any more. You know, the way he talks about them, it seems as if he thinks these are a bunch of nameless government bureaucrats that we need to cut back on. Those are his words,” the president added.

The president's latest campaign jaunt took him to Ohio and Nevada -- two important swing states -- to press the case for education as many students get ready to head back to school. His campaign released complementary TV ads to additionally pummel Romney on education cuts.

"I've got a question for Governor Romney. How many teachers' jobs are worth another tax cut for millionaires and billionaires?" Obama said Wednesday, using more pointed language toward his Republican challenger. "How many kids in Head Start are worth a tax cut for somebody like me who doesn't need it?"

But according to NBC’s Garrett Haake, Romney was ready with an educational response during an event Wednesday in Iowa.

“If you want to invest in young people, let me tell you what you need to do, Mr. President," Romney said. "You need to make sure that our K-through-12 schools are getting better, all right, that's number one. Not just talk, but actually getting better."

LAS VEGAS -- Mitt Romney said Friday that he has paid taxes "every year," vigorously disputing an assertion by Senate Majority Leader Harry Reid (D-NV) that the presumptive Republican presidential nominee paid no income taxes for a decade.

“Harry Reid really has to put up or shut up,” Romney told reporters following a rally here.

“Let me also say, categorically, I have paid taxes every year. And a lot of taxes. So Harry is simply wrong and that is why I am so anxious for him to give us the names of the people who put this forward. I wouldn’t be at all surprised to hear the names are people from the White House or the Obama campaign or who knows where they are coming from,” Romney added.

Romney's heated words toward the Senate's top Democrat follows Reid's repeated assertion this week that an investor in Romney's former firm, Bain Capital, confided that Romney had paid no taxes for 10 years. Reid hasn't substantiated the claim, nor has he identified his source, but that hasn't stopped the claim from advancing.

Reid wouldn't back down on Friday, either, issuing a statement calling for the release of more of the presumptive GOP nominee’s tax returns.

Rick Wilking / REUTERS

Republican presidential candidate Mitt Romney makes a point at a campaign event in Golden, Colorado August 2, 2012.

"Romney's message to Nevadans is this: he won't release his taxes, but he wants to raise yours,” Reid’s statement said. "It's hard to say which is more insulting to Americans' intelligence, Mitt Romney's tax plan or his refusal to show the American people what's in his tax returns.”

But asked why Romney won’t just release more of his tax returns to silence the attacks, the former Massachusetts governor said he is just following suit.

“I’m following the precedent set by the last presidential candidate of our party, John McCain, putting out two years of income tax returns and putting out a financial disclosure statement, those as required by law, of course,” Romney said.

Speaking to reporters during his first stateside press conference since last month's jobs report, Romney said these attacks by the Senate majority leader – in addition to those by President Barack Obama – are not what the country should be focusing on right now.

“I had hoped it would be a debate on the direction of the country but what we are seeing instead is one attack after the other that are misleading, false attacks,” he said. “The president’s ads saying I am going to raise taxes on the middle class. That’s patently, simply false. The president has now raised taxes on the middle class as so determined by the Supreme Court.”

Updated 12:35 p.m. -- Democrats and Republicans each found something to cheer in the Supreme Court's ruling Monday on Arizona's controversial immigration law, reflecting the delicate politics surrounding immigration and the court's own mixed decision.

Each party found something to like and dislike in the Supreme Court's opinion, which struck down most components of the Arizona law but left in place one of its most controversial provisions: the requirement that authorities check the immigration status of anyone they detain who's reasonably suspected of being in the United States illegally.

President Obama said he was "pleased" the court had struck down key provisions of the law, while his likely Republican opponent, Mitt Romney, suggested the decision represented a rebuke of the president.

"What this decision makes unmistakably clear is that Congress must act on comprehensive immigration reform. A patchwork of state laws is not a solution to our broken immigration system -– it’s part of the problem," Obama said. "At the same time, I remain concerned about the practical impact of the remaining provision of the Arizona law that requires local law enforcement officials to check the immigration status of anyone they even suspect to be here illegally."

Romney, meanwhile, emphasized what he said were the president's own struggles to curb illegal immigration.

"Today's decision underscores the need for a president who will lead on this critical issue and work in a bipartisan fashion to pursue a national immigration strategy," presumptive Republican nominee Mitt Romney said in a written statement.

Yuri Gripas / Reuters

People protest against President Obama's health care reform in front of U.S. Supreme Court in Washington June 25.

But Romney didn't address the components of the law that were thrown out or, alternatively, upheld by the court.

"I believe that each state has the duty -- and the right -- to secure our borders and preserve the rule of law, particularly when the federal government has failed to meet its responsibilities," he said.

Both Obama and Romney's responses were emblematic of the mixed reactions prompted by the decision across the political spectrum.

Senate Majority Leader Harry Reid (D-NV) said the decision marked a vindication of the Obama administration's initial decision to challenge the Arizona law. Critics in the Democratic Party said that the law, including the prong that the Supreme Court upheld, would open the door to racial profiling.

"This is as strong a repudiation of the Arizona law as one could expect given that the law has not been implemented yet," said New York Sen. Charles Schumer (D). "Three linchpins of the Arizona law were struck down by a convincing majority of the Court as clearly violating federal law, and a fourth is on thin legal ice."

But Republicans found just as much to cheer in the court's ruling.

Arizona Gov. Jan Brewer, who first championed the law, called the decision "a victory for the rule of law."

While many elements of the law were struck down, the court upheld what Brewer called the "heart" of the law -- a requirement that authorities check the immigration status of anyone whom they suspect of being in the United States illegally.

The state's two Republican senators, Jon Kyl and John McCain, also cheered the court for appearing to validate the status-check portion of the Arizona law.

The president will participate a series of public events set Monday in New England; as a matter of coincidence, Romney is in Arizona today to attend fundraisers.

The issue of immigration has assumed broader political significance in the 2012 campaign, following the president's announcement earlier this month that his administration would cease deporting illegal immigrants who were brought to the United States as children and would instead allow them to apply for temporary work visas. This shift, which achieved many of the intentions of a Republican version of the DREAM Act, was poised to mobilize Latino voters behind the president, who had otherwise fallen short on delivering on his promise of comprehensive immigration reform.

The administration's announcement also threatened to exacerbate Romney's gap against Obama among Latino voters, a growing bloc that could prove especially decisive in swing states like Arizona, Colorado, Nevada and beyond. An early May oversample of Latino voters in the NBC News/Wall Street Journal poll found that 22 percent of Latinos had a positive opinion of the GOP, versus 50 percent who expressed a negative impression of the Republican Party.

Romney responded to the new immigration policy by promising to supersede it with his own "long-term" plan on immigration. But he hasn't specified how his plan would work, or what it would differ in practical terms from the Obama plan.

The former Massachusetts governor has wrestled with immigration as an issue writ large, but has also struggled with positioning himself on the Arizona law.

Romney called the Arizona law a "model" at a debate this February, though his campaign insisted Romney only meant that in terms of some of the employment parts of the law (which the Supreme Court threw out on Monday). The Romney campaign was also forced to distance itself from Kansas Secretary of State Kris Kobach (R), one of the principal authors of the Arizona law and another tough immigration law in Alabama.

But Romney also said at the same debate that "the right course for America is to drop these lawsuits against Arizona and other states" in addition to more aggressive enforcement of immigration laws.

Romney had used immigration to pummel some of his opponents in the Republican primary from the right, making his pivot toward the general election even more difficult.

PUEBLO, CO — First lady Michelle Obama is used to drawing cheers in with almost every sentence in crowds like these, full of supporters of President Obama exclusively. 

But it's likes like this one today in southern Colorado that bring the house down"

"Like so many, like me, like so many of you , Barack knows the American Dream because he's lived it," Michelle Obama told a crowd of over a thousand at the Colorado State Fairgrounds in Pueblo. "It is his life. And he wants everyone who's willing to work hard to have that same opportunity."

In a city like Pueblo, where minorities make up more than 50 percent of the population and the median household income is well below the state's figure, the story of her and her husband's humble beginnings is sure to prompt a flurry of sign-waving and applause.

Mrs. Obama never mentions Mitt Romney's name on the stump, nor does she even use the euphemistic "the other guys" label beloved by Vice President Joe Biden.  But her campaign pitch — on full display during a busy Western swing — relies heavily on the narrative of the first family's unlikely rise to the presidency, drawing a clear contrast to Romney as a wealthy political scion.

"I'm proud of my background," she starts out before launching into her usual telling of her father's work at a water plant on the south side of Chicago.

Weaving the tale of her dad's stoic pride in saving for his children's education and paying bills with meticulous punctuality, she appeared to fight a lump in her throat during a stop outside of Denver.

"That's what I think about every night when I tuck my girls in," she told over 2,500 backers in a high school gymnasium in Centennial. "I think about how I want to do for them what my dad did for me."

And the first lady, wrapping up a two-day campaign swing in battlegrounds Nevada and Colorado, reminded supporters that she and her husband were mired in student debt after college.

"When we first started out, our combined student loan bill was actually higher than our mortgage. How many people can relate to that?" she said in Pueblo as many nodded and clapped their assent.

Unlike campaign stops for both nominees and for Biden, Mrs. Obama's campaign events to date have been free of heckling; tickets are typically only distributed through Obama for America field offices and usually require volunteer service for the campaign or at least a lengthy wait in line.

Despite gentle references to controversial topics — like the Obama administration's repeal of the 

"Don't Ask, Don't Tell" policy, push for the DREAM Act, and the White House's overhaul of health care — she pushed a message of inclusiveness in Denver, saying that the goals of equality and opportunity can be embraced by anyone regardless of political party.

"I don't care who we are," she said, in the only oblique reference to Republican opponents during the day. "The things I just talked about, every American in this country wants the same things." 

Is Mitt Romney playing with fire in his dealings with Donald Trump?

The presumptive Republican presidential nominee will appear with Trump, the pugnacious real estate mogul and reality television star, at a fundraiser Tuesday in Las Vegas. Former House Speaker Newt Gingrich, a nemesis of Romney's throughout the Republican presidential primary, will round out the group.

Steve Marcus / Reuters

Real estate mogul Donald Trump's ties to presidential candidate Mitt Romney run deeper than most run-of-the-mill supporters of the former Massachusetts governor.

Setting aside Gingrich’s own bombast, it’s Trump who could prove the bigger long-term headache for Romney. The latest example of that came Tuesday morning, when Trump said he’s still unconvinced that President Barack Obama was born in the United States, further linking Romney to that sentiment in a subsequent tweet from his @realDonaldTrump handle:

@BarackObama is practically begging @MittRomney to disavow the place of birth movement, he is afraid of it and for good reason. He keeps using @SenJohnMcCain as an example, however, @SenJohnMcCain lost the election. Don’t let it happen again.

It’s become clear that Trump’s ties to Romney run deeper than most run-of-the-mill supporters of the former Massachusetts governor. Romney and Trump appeared together when the “Apprentice” host made official his endorsement on Feb. 2. Since then, Trump’s become an involved surrogate for Romney, doing radio interviews and robocalls during the height of the GOP primary. He’s also hosted fundraisers for Romney, most notably one on Ann Romney’s birthday that netted the campaign $600,000.

“Donald Trump is playing an extremely important role, which has been acknowledged by both Ann and Mitt Romney, which has been acknowledged by them in election night speeches,” said Michael Cohen, a spokesman for Trump, in an interview.

Romney put some distance between the two men, though, before taking off for Colorado late on Monday night. "You know, I don't agree with all the people who support me and my guess is they don't all agree with everything I believe in. But I need to get 50.1 percent or more and I'm appreciative to have the help of a lot of good people," he told reporters aboard his campaign charter plane.

Romney was burned back in April when conservative rocker (and campaign supporter) Ted Nugent called Obama “evil,” and said if the incumbent were to win re-election, “I will be either be dead or in jail by this time next year.”

FIRST THOUGHTS: Playing the Trump card

Democrats stoked that story in the media, forcing Romney to personally address the Nugent controversy; now, it appears as though they’re hoping for another opportunity to do the same with Trump.

That is, when — not if — Trump goes off-message, Romney will have to answer for the controversy. His campaign won’t have the luxury of shrugging off a figure like Trump, who’s undeniably much closer to the Republican nominee than Nugent.

"It raises a question, that's come up before during this campaign, as to whether Gov. Romney will embrace these extreme voices in his party, or stand up to them," Obama campaign spokesman Ben LaBolt said Friday on MSNBC.

And already, the Obama campaign released a video on Tuesday bracketing the fundraiser this evening, contrasting Romney's relative silence toward Trump with the actions taken by Republican nominee John McCain in 2008 to shun extreme voices in the GOP.

For now, the Romney campaign has emphasized its singular focus on the economy, casting media firestorms around Trump or Romney’s previous work at Bain Capital as nothing less than a distraction.

"In a world of record job loss, record home loss, more people falling into poverty than time since the Depression, I don't think this stuff matters," said a Romney aide. "I would think the last few weeks would be a good lesson in that. From the anniversary of the Osama bin Laden killing to gay marriage, this election is just about one thing: are you happy with the economy and who do you think will do a better job?"

But the irony for Romney is that, for a campaign that prides itself on discipline and focus, its association with Trump threatens at any moment to knock the candidate off-message.

• Consider just a small sampling of the things Trump has recently said:
  May 22: Trump said on CNN that invoking Obama’s association with the controversial Rev. Jeremiah Wright in the campaign, which Romney had disavowed, is fair game. "These tapes are devastating for the president. I mean, Rev. Wright is an angry man. He's extremely angry at the president,” Trump said on CNN. “I see nothing wrong with using it."
  May 22: Also on May 22, Trump stoked the flames of “birtherism,” skepticism of whether the president was born in the U.S., despite Obama having released his long-form birth certificate a year earlier, showing he was, in fact, born in Hawaii. Trump tweeted: “I wonder if @BarackObama ever applied to Occidental, Columbia or Harvard as a foreign student. When can we see his applications? What do they say about his place of birth.”
  May 7: Trump suggested, during the Chen Guangcheng incident, that the United States’ economic tension versus China could translate into an actual war in due time. “It's not a war with bullets, but it's certainly a war,” Trump said of those economic tensions. “Maybe someday, it ends up with bullets because, frankly, they're building a military like you wouldn't believe.”

And there are more politically substantive examples of Trump breaking with Romney and the GOP.

“I just think it’s very dangerous,” he said of Wisconsin Rep. Paul Ryan’s budget proposals this March on FOX. “Already, the Democrats are just starting to write their campaign literature based on this plan. I think it’s very dangerous for the Republicans.”

Cohen said that Trump didn’t presume to speak for Romney.

“Donald Trump is his own individual, and he will make statements that he feels are accurate, are on the minds of other Americans and are significant in showing the voters who the real Barack Obama is,” he said. “Whatever questions will be posed to Gov. Romney and the Romney camp, they are certainly entitled to answer as they see fit. The current president and vice president don’t agree on all topics. Not all Republicans agree with all Republicans, and not all Democrats agree with all Democrats. Everyone is entitled to their own opinion.”

And to Trump’s credit, he’s never been known as a shrinking violet. His views have certainly been publicly aired at this point, and voters may be able to better distinguish between his headline-grabbing comments and the more staid sentiments of Romney.

But in a campaign cycle driven by grievance politics (“When will Mitt Romney/Barack Obama apologize for…?”), it’s difficult to imagine Romney not having to answer for some outburst of Trump’s between now and November.

“He’ll stand up next to Donald Trump, and he’ll talk about why he wants to be president, and why he believes the economy needs to be turned around,” Romney adviser Kevin Madden said Friday on MSNBC of the way Romney would relate to Trump. “Anytime that something goes off of that – or something where Gov. Romney would disagree – he’s going to make that very clear, just as he has in the past, and he’ll do it in the present, and he’ll do it in the future.”

NBC’s Garrett Haake contributed to this report.