WASHINGTON — The centerpiece of President Obama's initiative to lower gun violence, a law that would require background checks for nearly all gun purchases, is in danger of stalling in Congress, signaling a steep climb for any potential changes to the nation's gun laws.
New regulations on private sales appeared the most likely reform to pass Congress after the Sandy Hook Elementary School massacre in December. But no legislation has been introduced to expand the background check requirement even though a key committee in the Democratic-controlled Senate is scheduled to begin deliberations on gun proposals Thursday.
Separately, Rep. Robert W. Goodlatte (R-Va.), chairman of the House Judiciary Committee, said he would oppose any expansion of background check requirements. His committee would oversee any gun bills in the House.
Frustration by gun control advocates surfaced Wednesday when Vice President Joe Biden described concessions sought by gun rights proponents as "so porous that they are going to allow a truck to be driven through the holes in the legislation they are proposing, loaded with tens of thousands of weapons."
Seeking to break the logjam, New York Mayor Michael R. Bloomberg, who has made gun control a personal crusade, flew to Washington to meet with Biden and key members of Congress. Bloomberg brought evidence that gun control can win votes: He spent more than $2.2 million to help a Chicago-area candidate, Robin Kelly, win an upset victory Tuesday over a fellow Democrat who had an A rating from the National Rifle Assn.
Bloomberg and other gun control supporters cast the vote as a rebuke to the gun rights lobby. NRA spokesman Andrew Arulanandam disagreed, saying a liberal Chicago district had replaced one pro-gun control representative with another.
"They did not gain an inch," he said. "We did not lose an inch."
Although negotiations continued, no progress on background checks appeared evident in the Senate, where a bipartisan group struggled over how to broaden them. The major sticking point: whether private citizens who sell guns directly to others should be required, like licensed dealers, to keep records of the sale.
Gun rights backers warn those records could be used to create a national registry of gun owners, which they oppose.
Sen. Tom Coburn (R-Okla.), one of the key negotiators, said this week that any provision that required gun owners to keep records would "kill this bill." Instead, he said, legislation should give sellers "the right and the responsibility to do the right thing" and run a background check.
Gun control advocates say that without a paper trail, it's impossible to know whether background checks have been performed, opening a loophole for criminals to buy guns.
"They want the law to say no record would be kept," Biden said Wednesday to the National Assn. of Attorneys General. "How in the hell would you know if that transaction would be real if no record can be kept?"
Biden did not mention Coburn by name, but it was the first time the administration publicly acknowledged that the bill was faltering.
Coburn's support would represent a major boost for any new legislation. A bill with his backing would give political cover for Republicans and conservative Democrats wary of crossing the NRA, which has opposed universal background checks. That would push the bill past the 60-vote threshold needed to overcome a Senate filibuster.
Talks were ongoing between Coburn and Sen. Charles E. Schumer (D-N.Y.), as well as with Sen. Joe Manchin III, a West Virginia Democrat with a top NRA rating. Coburn and Manchin huddled during an afternoon vote, after which Coburn said he remained optimistic they could reach an agreement.
But Senate Democratic sources, increasingly pessimistic that a deal with Coburn would satisfy each party's chief concerns, said they had sought out other Republicans who might make more willing negotiating partners. There are risks in such a move, aides concede, because breaking with Coburn could spook other Republicans as well as some Democrats facing reelection in 2014.
Pressure to forge a quick compromise stems, in part, from the Senate's legislative calendar.
Sen. Patrick J. Leahy (D-Vt.), chair of the Judiciary Committee, promised to begin considering gun legislation by the end of February. He placed four gun bills, including a proposal to ban so-called assault weapons and another to curb gun trafficking, on Thursday's agenda. For procedural reasons, deliberations can be delayed a week, but a background check bill must be ready for the committee by March 7.
"Everyone's getting a little antsy," said Jim Kessler, vice president of Third Way, a Democratic think tank. "We have been close for the last two weeks without being able to resolve this final issue and it's frustrating. There's no doubt about it."
Kathleen Hennessey in the Washington bureau contributed to this report.