A combative and crowded Senate Judiciary Committee hearing on gun violence Wednesday exposed the deep divisions among lawmakers and advocates over the nation’s firearms policies. But the three-hour session also showed there is bipartisan support for strengthening the background check system for gun purchases and cracking down on gun traffickers.

Those policy proposals, in particular, seemed to find middle ground between the two parties, even as the committee’s more liberal Democrats pushed for tougher restrictions, such as a renewed assault weapons ban, and conservative Republicans laid into the Obama administration for not doing enough to enforce gun laws that are already on the books.

The high-profile hearing — the first called by Congress in response to the fatal shooting of 20 first graders and six educators at a Connecticut elementary school on Dec. 14 — began with a surprise appearance by former Rep. Gabrielle Giffords, D-Ariz. In slow and halting words, the former lawmaker, who was critically wounded when a gunman shot her in the head and killed six others at a constituent event in 2011, called for lawmakers to “be courageous” and take prompt legislative action in response to the Connecticut attack.

The hearing also saw several public outbursts in response to witnesses’ testimony and featured vocal opposition to new gun control measures from Wayne LaPierre, the outspoken executive vice president of the National Rifle Association, who said that more laws would lead to a “huge, massive bureaucracy” of regulations.

Amid the pitched back-and-forth, however, Democrats and Republicans signaled they could be open to targeted legislative proposals that do not specifically restrict guns and ammunition but attempt to keep firearms out of the wrong hands.

“I want to find out how we can stop what is happening,” Judiciary Chairman Patrick J. Leahy, D-Vt., concluded at the end of the hearing. “I believe there should be some areas of agreement, and I hope the committee can get together to mark up legislation next month — this month is virtually over — and then take it to the floor.”

Background Checks Emphasized

Under current law, federally licensed gun dealers are required to conduct background checks on prospective buyers to ensure they are not among a banned category of purchasers, including felons, fugitives and the mentally ill. Sales between private individuals, including those at gun shows, are not subject to such screenings, however, and an estimated 40 percent of gun sales do not involve background checks.

Leahy said he saw no reason that background checks should not be expanded to cover all gun sales.

“I know gun store owners in Vermont. They follow the law and conduct background checks to block the conveyance of guns to those who should not have them. They wonder why others who sell guns do not have to follow these same protective rules,” Leahy said. “I agree with these responsible business owners.”

A bipartisan group of senators — including Democrats Charles E. Schumer of New York and Joe Manchin III of West Virginia, along with Republicans Tom Coburn of Oklahoma and Mark S. Kirk of Illinois — is discussing legislative proposals to expand background checks. Schumer said at Wednesday’s hearing that he is “hopeful that we are close to having legislation that we can introduce,” and he said such legislation “has a good chance of passing.”

Beyond the Republicans involved in those talks, Sen. John Cornyn of Texas also indicated at the hearing that he could be open to improved background checks. “Perhaps it’s time to consider our background check laws to see if they need to be updated,” he said.

Sen. Jeff Flake, R-Ariz., questioned why states are not doing more to submit records of disqualified purchasers to the federal database of individuals who are barred from buying guns — a database that dealers can access at the point of sale. Flake noted that his own state has more than 120,000 records of mentally ill individuals who are barred from buying guns but that Arizona has not shared those records with the federal database.

Mark Kelly, a retired astronaut who is married to Giffords and has co-founded a political action committee with her to push for stronger gun laws, testified that his top priority would be to strengthen background checks. “I can’t think of something that would make our country safer than doing just that,” he said.

LaPierre agreed that states should do more to contribute records to the database of barred purchasers. But he expressed opposition to expanding the background check system to cover private sales, saying it would be ineffective because criminals would find other ways to acquire firearms. He emphasized that the federal government rarely prosecutes those who attempt to buy guns illegally.

White House spokesman Jay Carney pushed back against that assessment at his briefing Wednesday. Carney did not dispute statistics cited by the NRA and other gun advocates about the relatively few cases brought against criminals who fail background checks. But he said that is not a reason not to require them for all gun purchases, calling the argument a “logical fallacy.”

The solution is not “either/or,” Carney said, noting that prosecutions as well as background checks can be improved.

Bipartisan Bill on Gun Trafficking

Meanwhile, the committee’s top Republican, Charles E. Grassley of Iowa, said he could support an effort to crack down on gun traffickers or “straw purchasers,” who buy firearms for those who are banned from doing so.

“I do think, Mr. Chairman, that we may be able to work together to prevent straw purchasers from trafficking in guns,” Grassley said in his opening statement, adding that “there are some gaps in this area of the law that should be closed.”

Leahy has introduced legislation to crack down on trafficking, and two other senators — Kirk and Kirsten Gillibrand, D-N.Y. — announced Wednesday that they had also introduced a trafficking bill, the first bipartisan legislation on gun violence since the Connecticut shooting.

The Kirk-Gillibrand bill would prohibit the sale or purchase of two or more guns for those known to be barred from owning firearms, and it would make it illegal to provide false information on transaction forms provided by the Bureau of Alcohol, Tobacco, Firearms and Explosives.

“Our bipartisan bill will save lives. It is not a Republican or Democratic idea, it is just the right idea,” Gillibrand said in a written statement. “The absence of any federal law defining gun trafficking in this country is shocking. It is time to give law enforcement the tools they need to keep illegal guns off the streets and out of the hands of dangerous people.”

Other Proposals Criticized

While improved background checks and gun trafficking legislation may gain bipartisan traction on Capitol Hill, Wednesday’s hearing suggested strongly that two other priorities for liberal Democrats — a reinstated assault weapons ban and a ban on large ammunition magazines — will not.

Republican senators and several witnesses stated bluntly that the original assault weapons ban, which lasted from 1994 to 2004, was ineffective.

Sen. Ted Cruz, R-Texas, called the law a “singularly ineffective piece of legislation,” and University of Denver constitutional law professor David Kopel said the law was a “failure.”

Those criticisms came as the author of the original ban, Sen. Dianne Feinstein, D-Calif., sat just a few feet away in the hearing room. Feinstein last week reintroduced an expanded version of the ban, which would prohibit 157 specific kinds of gun by name and ammunition magazines that hold more than 10 rounds. The legislation also would require background checks on the sale or transfer of such assault weapons that are currently in private owners’ possession.

Sen. Lindsey Graham, R-S.C., indicated he is unlikely to support the assault weapons ban because, he said, there are situations in which high-powered guns that would be banned under the proposal, as well as the magazines that feed them, are necessary.

“In some circumstances, the 15-round magazine makes perfect sense, and in some circumstances, the AR-15 makes perfect sense,” Graham said, referring to a widely circulated semiautomatic rifle that would be outlawed under Feinstein’s plan.

Steven T. Dennis contributed to this report.