Senators negotiating a bill mandating background checks for all gun buyers are privately expecting the National Rifle Association not to fight the measure -- provided the legislation does not require private gun sellers to maintain records of the checks, NBC News has learned.

If that requirement is met and key Republican negotiator Sen. Tom Coburn of Oklahoma signs on, the powerful gun lobby has signaled to lawmakers that they would not actively oppose the bill -- and not count votes in favor of it as part of its highly influential NRA lawmaker ratings -- according to Senate aides familiar with the stalled negotiations.

Such a deal could clear the way for a universal background check bill, a central tenet of President Barack Obama's gun control initiative, to pass the Senate with significant Republican support. Odds of passage in the House would brighten significantly as a result.

The NRA denies being part of any agreement. "We do not take positions on hypotheticals. We will make our position known if and when legislation is introduced," said Chris Cox, the group's top lobbyist. 

The NRA is still adamantly opposed to expanding background checks to private sales. "To be clear, the National Rifle Association does not support legislation that would criminalize otherwise lawful transfers of firearms between law abiding Americans," Cox said.

EARLIER: Panel advances background check bill, but its path remains clear

Such a decision would mark the first major compromise from the group in the wake of the elementary school shootings that killed 26 in Newtown, Conn. The NRA has signed on to a bipartisan mental health bill and are talking to senators about gun trafficking legislation. But with an assault weapons ban not likely to pass, the background check bill is the main legislative fight over new gun restrictions.

Still, Democrats have balked at this development: Leaving such a provision out, they say, would make the law toothless and would never earn support from gun control advocacy groups.

But without the record-keeping provision -- and the blind eye from the NRA -- Democrats would instead have to squeak their way to the 60 votes needed to pass in the upper chamber, potentially risking the whole package.

Both sides say it's tough to compromise on the issue of records. Coburn and the NRA argue that requiring private sellers to keep a record of each background check and gun sale would start down a slippery slope to a national gun registry. Gun control advocates, on the other hand, say enforcing any background check law would be all but impossible if records aren’t kept, and thus would have little impact on the criminals the bill is designed to target.

Jacquelyn Martin / Jacquelyn Martin / AP

Sen. Tom Coburn, R-Okla. walks toward the Senate chamber on Capitol Hill in Washington, Monday, Dec. 31, 2012.

"With about 90 percent of the public calling for a comprehensive background check system, the incentive to agree to a bill that only law abiding people will comply with, and that people we're trying to reach will ignore, is vanishingly small," said Mark Glaze, the executive director of Mayors Against Illegal Guns, a group headed by New York City Mayor Michael Bloomberg.

"Background checks do not and cannot lead to gun registration. It's a lie meant to muddy the debate and distract from our common goal -- saving lives with solutions that Americans support overwhelmingly," Mark Kelly, the husband of former Rep. Gabby Giffords, said in a Tuesday statement.

Coburn, who holds an "A" rating from the NRA, has been locked in closed meetings with Sens. Chuck Schumer, D-N.Y., and Joe Manchin, D-W.Va., over the background check legislation.

Coburn and Manchin insist they're still talking, and Manchin said he was on the phone Tuesday with the NRA. He and Coburn have shared legislative language with the group as they've worked on an agreement.

"Tom Coburn and I come from a culture, a background, a culture of guns. So I think the NRA would respect and appreciate where we're coming from, with the understanding that we understand our NRA members," Manchin told NBC News on Tuesday. "I'm an NRA member, Tom's an NRA member, and they're looking at that. And hopefully we can find some common ground."

But the background check discussions with Schumer have stalled -- and the New Yorker is now reaching out in an effort to find another Republican who might be willing to sign on. The list includes moderates, like Sen. Susan Collins of Maine, and Republican senators who aren't running for re-election, like Georgia Sen. Saxby Chambliss.

Chip Somodevilla / Getty Images

Sen. Chuck Schumer boards an elevator at the U.S. Capitol on March 12, 2013 in Washington, D.C.

Sources familiar with the negotiations suggest that Schumer has only made a public break with Coburn because he's trying to convince groups on the left -- the Bloomberg group, the Brady Campaign to Prevent Gun Violence, and others -- that they need to give in on record-keeping in order to save a broader package.

Glaze said that's a no-go, indicating that his group -- backed by Bloomberg's billions -- would instead air ads in senators' home states attacking them for not going further in their quest to stop gun violence.

"We're going to take the time to get out into the country and have that conversation with members and their constituents, and we will see where we end up in the late summer," Glaze said.

Asked about the groups' position Tuesday, Manchin emphasized the realities of getting a bill passed.

"I respect their position, but basically, we have 535 members, and they all have certain concerns and considerations to be taken. If you want to pass something, you have to work within a, a compromise if you will, bipartisan arena," he said.

NBC's Mike Viqueira contributed. 

This story was originally published on Tue Mar 12, 2013 5:01 PM EDT

The Senate Judiciary Committee on Tuesday advanced legislation requiring all gun buyers to get a background check, voting along party lines to send a version of the bill to the full Senate.

But the bill passed in committee does not represent the legislative language that both sides ultimately expect the full Senate to consider. 

Instead, it's a Democratic version of a background check bill, voted upon by the committee because a bipartisan group of negotiators haven't yet been able to compromise on its specifics.

"I've been talking and continuing to talk to colleagues across the political spectrum and across the aisle about a compromise approach, and I remain optimistic that we'll be able to roll one up," Sen. Chuck Schumer said at the Judiciary Committee's meeting on Tuesday. "But we're not there yet."

Senators are working on a package that would require all gun buyers to get a background check before they buy a gun. Under current law, only licensed dealers have to get a background check from a buyer before they sell a firearm. The bipartisan group had agreed on some exceptions, including one for people selling or giving guns to family members.

If that group -- led by Democrats Schumer and Joe Manchin and including Republican Sen. Mark Kirk -- can find common ground, the bill they produce is expected to become the centerpiece of President Barack Obama's gun control agenda in the Senate.

Those negotiations stalled when Republican Sen. Tom Coburn -- who carries an "A" rating from the National Rifle Association -- couldn't agree with Democrats about whether to require private sellers to keep records of the guns they sell.

Schumer and Manchin are now looking for a second Republican co-sponsor, preferably someone with a top NRA rating. They've reached out to a number of GOP lawmakers, including Sens. Jeff Flake, Susan Collins and Johnny Isakson. Schumer is now taking meetings with some of those Republicans.

Senators also advanced a school safety measure on Tuesday. That bill had bipartisan support.

This story was originally published on Tue Mar 12, 2013 11:21 AM EDT

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.