Updated 2:35pm ET: Obama administration officials will meet with the National Rifle Association Thursday, “one of the many” gun-rights advocacy groups that will attend a series of events at the White House, according to White House officials.

The NRA confirms it will attend.

“We got an invite late Friday,” NRA spokesman Andrew Arulanandam said in a short statement. “We are sending a representative to hear what they have to say.”

White House spokesman Jay Carney downplayed the meeting, telling reporters that the NRA is just “one of the many” groups that will attend.

"We have invited -- or the vice president's group has invited a number of organizations and individuals to participate in meetings," Carney said, adding, "The NRA has certainly been one of the groups, one of the many groups invited."

Vice President Joe Biden and White House officials will also meet with representatives from the video game and entertainment industries, as well as victims groups and gun-safety organizations ahead of what could be the administration unveiling – as early as next week – a series of measures it will throw its weight behind in response to the Dec. 14^th shooting at an elementary school in Newtown, Conn. Twenty-sex people were killed in the shooting spree, including 20 young children.

Brendan Smialowski / AFP - Getty Images

A Secret Service officer watches as workers build a structure across the North Lawn of the White House to Pennsylvania Avenue for the upcoming US Presidential inauguration January 8, 2013 in Washington, DC.

The goal of the Biden group is to try and come up with legislative measures that could prevent massacres like Newtown from happening again. Among the ideas being considered by the White House are stricter gun laws, like banning high-capacity weapons and magazines, wider background checks, as well as mental-health screenings.

Education Secretary Arne Duncan will be talking to parents, teachers, and education interest groups; Health and Human Services Secretary Kathleen Sebelius will meet with mental health and disability advocates, according to the White House.

The NRA, however, is a potential major stumbling block to major legislation given its sway on Capitol Hill. And it has dug in after Newtown, continuing to be a staunch opponent of any further restrictive gun measures.

The NRA proposed that the government pay for putting an armed guard in every school in America, an idea President Obama did not greet warmly on Meet the Press Dec. 30^th.

“I am not going to prejudge the recommendations that are given to me,” Obama said. “I am skeptical that the only answer is putting more guns in schools.”

The White House says that “soon after the conclusion of these meetings, the vice president will present his recommendations to the President, who then will announce a concrete package of proposals he intends to push without delay.”

Updated at 2:15 a.m. ET -- An agreement in principle to avert broad tax increases and spending cuts passed in the Senate early Tuesday morning, with an overwhelming vote of 89-8.

The House of Representatives is expected to vote before Wednesday.

The interim New Year's Eve tax deal negotiated by Biden and Senate Republican Leader Sen. Mitch McConnell of Kentucky would raise income taxes on single earners with annual incomes above $400,000 and married couples with incomes above $450,000.

It also blocks spending cuts for two months, extends unemployment benefits for the long-term jobless, prevents a 27 percent cut in fees for doctors who treat Medicare patients and prevents a spike in milk prices.

As of mid-afternoon Monday, the sticking point involved the "sequester," the cuts to spending – about $100 billion to start in 2013 -- that were mandated by the Budget Control Act which President Barack Obama signed into law last year. Republicans have signaled they might let the sequester take effect unless it was offset by other spending cuts; the GOP has also said it might accept a delay, but only for a few months.

The Obama administration, however, was pushing for a longer delay in implementing the sequester. Otherwise, the president said, replacing those automatic cuts must be "balanced" — shorthand for a combination of new taxes and other spending cuts.

Obama tried to push talks over the finish line earlier in the afternoon with a statement from the White House.

"Today, it appears that an agreement to prevent this New Year's tax hike is within sight," the president said at the White House on Monday. "But it's not done."

In the absence of a broader agreement to resolve the sequester, McConnell appeared in the Senate floor to request a vote only on the tax element of the fiscal cliff.

"Let's pass the tax relief portion now," he said. "Let's take what's been agreed to and keep moving."

But it's not clear that Democrats, who were led in negotiations by Vice President Joe Biden, would agree to de-link the tax debate from other fights over the sequester and extending expiring unemployment benefits past Dec. 31.

House Republicans were careful to note that it was still possible for them to add votes late on New Year's Eve. But they also argued that there was no Senate-passed legislation on which they could schedule a vote, making the prospect of avoiding the cliff all the less likely.

Democratic and Republican sources in the House told NBC News that a final vote on any deal would now most likely wait until afternoon on New Year's Day, or even on Jan. 2.

Though Congress could still conceivably act after New Year's to preserve existing tax rates — thereby limiting any lasting effect on consumers — their inability to reach an agreement until the very last minute could still threaten to rattle the economy and markets.

The House did act late Sunday, though, to clear the way for emergency consideration of Senate legislation if leaders are able to reach an agreement. The House Rules Committee convened with the purpose of dispensing with a rule instilled by Republicans in the early days of 2011 to require that legislation be posted online for a full 72 hours before a vote in the House. GOP leaders had sought that rule to showcase their own transparency, and in reaction to actions by the previous Democratic majority to quickly pass legislation during the health care reform battles of 2010.

Republicans' move to sidestep their own rule underscores the urgency of fiscal cliff talks in the final hours of 2012. There were few ironclad assurances, though, that any Senate agreement would necessarily win the support of the House.

The lurching nature of legislating has been characteristic of the Congress during the last two years, and that's a phenomenon that may well continue into the next Congress, when Democrats will continue to retain control of the Senate, and Republicans will hold a slightly slimmer grasp on the House.

J. Scott Applewhite / AP

Senate Minority Leader Mitch McConnell of Kentucky, center, arrives at his office in the Capitol as he and Senate Majority Leader Harry Reid of Nevada, try to negotiate a legislative solution to avoid the so-called "fiscal cliff" in Washington, Sunday, Dec. 30, 2012.

After a day of talks that were expected to yield some sort of compromise on the so-called fiscal cliff, Senate leaders called off any further votes until Monday morning, just hours before the deadline that will trigger across-the-board tax increases and dramatic cuts in military and domestic spending. 

The Senate will meet again on New Year's Eve, the last full day before the "cliff" takes effect on Jan. 1. Negotiations were expected to continue in the meanwhile.

A day of wrangling in the Senate came and went without an accord to avoid the fiscal cliff, leaving lawmakers just a matter of hours to sort through thorny issues of taxes and spending that have beguiled Congress for the better part of the past two years. 

Significant distance remains between the two sides and negotiations continue, although the clock continues to tick. Even a simple deal appears far from certain.

"There is still time left to reach an agreement, and we intend to continue negotiations," Senate Majority Leader Harry Reid, D-Nev., announced early Sunday evening. "We're going to come in at 11 a.m. tomorrow morning. We'll have further announcements, perhaps, at 11 in the morning. I certainly hope so."

As the Senate struggles to reach an agreement, House members — who were back in Washington on Sunday — were left awaiting any potential legislation from the upper chamber.

Reid and Senate GOP Leader Mitch McConnell had been tasked by President Barack Obama with developing a bare-bones deal to stave off the automatic tax hikes following the expiration of the 2001 Bush tax cuts at the end of the day on Monday. 

But discussions between the leaders and their staff failed to produce an agreement. Democrats said that a main hangup involved what's known as "chained CPI," a re-calculation of how Social Security benefits grow in outlying years. Democrats regard that proposal, which Obama had previously offered to Republicans in the context of a broader bargain, as a "poison pill" if included in these last-ditch efforts. 

The impasse prompted McConnell to reach out to Vice President Joe Biden, a former senator who's previously helped navigate congressional standoffs, in hopes of jump-starting negotiations. Biden was at the White House on Sunday afternoon.

But after each leader huddled with his respective party on Sunday, there were few indications of the type of breakthrough needed to end the stalemate in the Senate. Republicans, though, did appear to relent on any demand to include chained CPI in a final deal (though GOP officials denied they had ever seriously proposed it in the first place).

"We have as a conference have come out and said, if that's a show-stopper for the majority leader, we take that off the table," New Hampshire Sen. Kelly Ayotte said following the meeting with fellow Republicans.

The breakdown in negotiations sets the stage for one of the most dramatic days of political deal-making on Monday, the final day of 2012 and just three days before the next Congress — which won't affect control of either chamber but is slightly more Democratic — is sworn into office on Jan. 3.

House Speaker John Boehner, R-Ohio, had recalled House members to Washington for a series of rare weekend evening votes on Sunday. Those lawmakers had conceivably been asked to return  to vote on whatever agreement Senate leaders might be able to forge. But absent any legislation, which would not come before Monday morning, House members' presence was largely superfluous. 

Obama had asked Reid to prepare a vote on fallback legislation to preserve tax rates on income under $250,000 and extend expiring unemployment benefits in case Senate talks fell through. Democrats showed no signs of backing off that intention, though it is unclear whether Boehner would allow that legislation to even come to a vote in the House. 

"Now the pressure's on Congress to produce," Obama said in an interview on NBC's "Meet the Press," which aired Sunday.

The hold-up on Capitol Hill appeared, though, to involve several unresolved issues. First, lawmakers must reach an agreement on the threshold of income beneath which current tax rates would be extended. Second, they must resolve what elements of spending — unemployment benefits, for instance — or commensurate cuts (to offset the cancellation of the automatic spending cuts, known as the sequester) to include in a final package.

"The biggest obstacle we face is that President Obama and Majority Leader Reid continue to insist on new taxes that will be used to fund more new spending, not for meaningful deficit reduction," Sen. Jeff Sessions, R-Ala., Republicans' budget chief, said in a statement.

NBC's Frank Thorp contributed reporting.

Updated 3:10 p.m. — Senate Democrats said talks toward resolving the so-called fiscal cliff before the end-of-year deadline had hit a "major setback" on Sunday afternoon due to a standoff over proposed changes to Social Security. 

Democrats said that Republicans, led by Minority Leader Mitch McConnell, Ky., are insisting that a deal to resolve the fiscal cliff include what is known as "chained CPI" -- a change in how Social Security benefits are calculated to increase over time. 

Just before a self-imposed deadline at which Senate leaders were set to brief their respective caucuses about a prospective deal, negotiations toward a scaled-back agreement to avoid the onset of automatic tax hikes and spending cuts on Jan. 1 appeared on the verge of breakdown.

Related:Obama: GOP's insistence on halting tax hikes for the wealthy is stopping fiscal cliff deal

McConnell said that he had even reached out to Vice President Joe Biden, a former senator who's helped hammer out previous deals, in hopes of jump-starting the talks. 

"He and the vice president, I wish them well," Senate Majority Leader Harry Reid, D-Nev., said on the Senate floor. 

"In the meantime, I will try to come up with something," Reid added of Republicans' latest proposal, "but at this stage I don’t have a counter-offer to make."

Obama had offered chained CPI — which would essentially reduce the rate of growth in Social Security benefits over time — as part of a broader "grand bargain" he had previously proposed to Republicans. The GOP rejected that proposal, and moved from there onto House Speaker John Boehner's "Plan B," an ultimately unsuccessful effort. 

In his interview earlier today on NBC's "Meet the Press," the president pointed to his offer on chained CPI as evidence of his willingness to compromise in pursuit of a broad fiscal deal. 

"One of the proposals we made was something called Chain CPI, which sounds real technical but basically makes an adjustment in terms of how inflation is calculated on Social Security," Obama said. "Highly unpopular among Democrats. Not something supported by AARP. But in pursuit of strengthening Social Security for the long-term I'm willing to make those decisions."

A Senate Democratic aide said that Democrats had thought such a proposal was off the table, though, as part of the talks toward parried-down agreement. 

"It’s basically a poison pill," the aide said of Republicans' demand for chained CPI.

Sen. Lindsey Graham, R-S.C., expressed bewilderment at the breakdown, suggesting that there were more than enough votes for a compromise measure that didn't include chained CPI.

"I don't know what caused this but there's a critical mass of 80 senators who would vote to fix the [alternative minimum tax], the doc fix, extend unemployment insurance, protect everybody 500 thousand and below from a tax increase," he told reporters at the Capitol. "There's 80 senators who will do that without CPI."

McConnell, who spoke briefly on the Senate floor around 2 p.m., struck an ever-so-slightly sunnier note.

"There is no single issue that remains an impossible sticking point," the top Senate Republican said.  "I want everyone to know I'm willing to get this done. But I need a dance partner."

Senators are set to huddle with members of their respective parties this afternoon amid votes to discuss the latest as it relates to the fiscal cliff.

As House members return to town this evening for votes this evening, they'll also caucus with fellow party members to discuss what, if any, way forward there is on the fiscal cliff.

NBC's Frank Thorp contributed reporting.

Saul Loeb / AFP - Getty Images

Vice President Joe Biden tries food samples during a visit to a Costco store on a shopping trip in Washington, D.C., on November 29, 2012.

Joe Biden: Delawarean. Vice president. Vocabulary muse.

In new data announced Wednesday by Merriam-Webster, a much-quoted Bidenism from the 2012 campaign set a record for the year in online lookups during a single 24-hour period.

In the 24 hours after the Danville, Ky., vice presidential debate, after Biden famously labeled a claim by Paul Ryan "a bunch of malarkey," look-ups of the noun's definitions on the dictionary's website spiked by 3,000 percent.

According to the Associated Press, Merriam-Webster does not release data for individual words, but the site gets about 1.2 billion hits annually.

"Malarkey," a pseudo-expletive of Irish origin frequently used by the Scranton native, is defined by the dictionary company as "insincere or foolish talk : bunkum."

Merriam-Webster also announced Wednesday, per AP, that "socialism" and "capitalism" were their most looked-up words of the year, after a hard-fought election that largely centered around the role of government in the economy and Americans' lives.

For the record, both are defined thusly:

Capitalism: (noun) an economic system characterized by private or corporate ownership of capital goods, by investments that are determined by private decision, and by prices, production, and the distribution of goods that are determined mainly by competition in a free market

Socialism: (noun)

1. any of various economic and political theories advocating collective or governmental ownership and administration of the means of production and distribution of goods

2. a : a system of society or group living in which there is no private property

b : a system or condition of society in which the means of production are owned and controlled by the state

3 : a stage of society in Marxist theory transitional between capitalism and communism and distinguished by unequal distribution of goods and pay according to work done

ABOARD AIR FORCE TWO - Vice President Joe Biden said Tuesday's election results showed "a clear sort of mandate" in favor of Democratic tax policies advocated by President Barack Obama throughout the campaign this year.

Following a decisive Electoral College victory, Biden suggested Republicans would take some time to engage in "soul searching" on issues like immigration and fiscal policy.

Matt Rourke / AP

Vice President Joe Biden, accompanied by his son Beau Biden, his wife, Hallie and their daughter Natalie, stands in line to cast his ballot at Alexis I. duPont High School, Tuesday, Nov. 6, 2012, in Greenville, Del.

"Barack's re-elected, so this sort of cause to keep a second term from happening is done," Biden told reporters aboard Air Force Two. "He's there for four years. So ... I hope there's going to be some real soul-searching about, on Republican Party, about what they're willing to cooperate on."

Biden said there is "all kinds of potential to be able to compromise" on the looming fiscal cliff but argued that the election results showed "a clear sort of Mandate about people coming much closer to our view about how to deal with tax policy." 

Saying that the GOP ticket's defeat among minority groups should serve as "a wake up call" to Republicans on immigration reform, Biden said the time is ripe for compromise.

"I feel very optimistic about, in my view, immigration reform," he added. "Because as we talked about with most of the Hispanic communities I spoke with over the last month, it played a major role [in Romney's defeat.]"

Biden, who predicted the strong electoral victory for Democrats, conceded that he did not expect the race to be called as quickly as it was last night.

"It was much earlier than at least I thought we'd know what the outcome was," he said. "It felt good."

GREENVILLE, Del. -- Saying that "it's always a kick" to vote on a ballot that bears his name, Vice President Joe Biden made his political picks Tuesday in his home state of Delaware.

Matt Rourke / AP

Vice President Joe Biden, accompanied by his son Beau Biden, his wife, Hallie and their daughter Natalie, stands in line to cast his ballot at Alexis I. duPont High School, Tuesday, Nov. 6, 2012, in Greenville, Del.

Outside his polling place at Alexis I. duPont High School, Biden told reporters that this is the eighth time he has run statewide and urged all Americans to exercise the "honor" of voting.

Asked if today's vote for the Obama-Biden ticket would be the last time he votes for himself, he grinned widely and replied "no, I don't think so."

The vice president was accompanied by his wife, his son Beau and daughter-in-law, and granddaughter Natalie. Biden joked to Natalie, 7, that she should make sure to keep him in mind if she votes. But, he noted with mock penitence, "I'm not supposed to be campaigning" inside the polling place, per federal law.

Biden travels tonight to Chicago, where he and the president will await election results.

STERLING, Va. -- For a second time in two days, Vice President Joe Biden on Monday predicted a strong electoral showing for Democrats, saying "it's all over but the shoutin.'"

"I'm feeling good," the vice president told reporters at Mimi's Cafe during an unscheduled stop. "I really am but you know, as an old expression goes it's all over but the shoutin'."

Biden predicted - as he did yesterday in an interview with MSNBC's Chris Matthews - that the Obama-Biden ticket will prevail in "firewall" states, but he acknowledged that swing states of Virginia and Florida could be squeakers.

"I'll take a one-vote majority, but I think we have a clear shot at doing well and the so-called firewall," he said, envisioning victory in Ohio, Wisconsin, Iowa, Nevada and New Hampshire.

"I think Florida will be close but I think we have a real shot of winning," he added. "And this state, we got a clear shot of winning it."

Biden's last full day of pre-election campaigning in virginia marks his ninth trip to the state this year.

He is barnstorming today with Senate candidate Tim Kaine, Virginia Sen. Mark Warner and retiring Sen. Jim Webb.

Vice President Joe Biden on Sunday predicted a decisive Electoral College victory for the Democratic presidential ticket, saying that the president's midwestern "firewall" will hold.

"I think that we're going to win.  I don't think it's going to be close in the Electoral College," said the vice president in an interview with MSNBC's Chris Matthews after a rally outside Toledo.

"I think the firewall here of Ohio, Wisconsin, Iowa -- I think it's going to hold firm," he said.

Biden's certainty  didn't extend to the two major battlegrounds of Virginia and florida, which public polling have shown to be trending slightly in the Republicans' favor. He told Matthews that Democrats have an "even chance" in those states after predicting wins in Ohio, Wisconsin, New Hampshire, Nevada and Iowa.

But even without the combined 42 electoral votes of the two Southern swing states, the Obama-Biden ticket could still win a decisive Electoral College victory if Democrats hold midwestern and western states like Ohio, Pennsylvania, Wisconsin, and Colorado.

Biden was also upbeat about the possibilities for compromise in Congress after the election, despite his frequent lambasting of the Tea Party's influence in the United States House and Senate.

"We need leaders that can control their party," he said. "And I think you're going to see the fever break." 

PUEBLO, Colo. -- It's rare that an audience asks the famously audible Joe Biden to speak up.

But with the acoustics in Pueblo's Central High School gymnasium leaving many of the thousand attendees at his Saturday afternoon rally unable to hear him, they did.

"I wish to hell they'd turn this mic up!" an annoyed Biden declared loudly upon hearing their pleas for more volume.

Biden, who is known to read media coverage of his slip-ups and frequently notes in front of audiences that he "got in trouble" with the press for mistakes,  joked about the kind of headlines that the sound situation could garner as he belted out the remainder of his remarks.

"I'm going to hear a press report," he said as the audience giggled at his imagined headline. "'Biden screamed at the audience.'"

ARVADA, Colo. -- Ka-zing.

Three days before the election, Vice President Joe Biden pegged his newest critique of Republican presidential nominee Mitt Romney to the semi-annual inconvenience of adjusting clocks for Daylight Savings Time, which occurs tonight.

"It’s Mitt Romney’s favorite time of the year -- because he gets to turn the clock back!" Biden told a crowd of hundreds at a suburban Denver high school.

In his remarks, the vice president accused Romney of embracing social policies out of an earlier era, pointedly noting the GOP nominee's voiced enthusiasm for "getting rid of" Planned Parenthood. 

"With all the issues facing the country, Gov. Romney has focused on for the last three months [that] he's going to get rid of Planned Parenthood" Biden said. "And by the way, he doesn't even know he doesn't control Planned Parenthood."

"He should talk to Big Bird!" he added, referencing the scuffle over public broadcasting funding that broke out during one of the presidential debates.

(In context, Romney said last spring he was going to "get rid" of federal funding for Planned Parenthood, not get rid of the entity itself.)

Biden has two events scheduled in swing state Colorado Saturday. He will campaign Sunday in Ohio.