White House officials are seeking a way to use executive authority to close the so-called gun show loophole that allows thousands of people to buy firearms each year without a background check, but complicated legal issues have slowed the process.
Almost three years ago, after the killing of 20 children and six adults at Sandy Hook Elementary School in Newtown, Conn., President Obama asked Congress to change the law to require background checks for weapons sold outside the network of licensed gun dealers, including sales at gun shows or through the Internet. A bill to tighten the background system died in the Senate a few months later — dashing the administration's hopes for legislative action.
The deadlock in the Senate continued Thursday as Republicans blocked several efforts by Democrats to add gun control provisions to a budget measure.
In one of a series of near-party-line procedural votes, the Senate by 54 to 45 blocked a proposal by Sen. Dianne Feinstein (D-Calif.) that would have stopped people on the government's anti-terrorist "no fly" list from buying guns. Republican opponents said that the no-fly list includes too many errors to be used for preventing gun sales.
By a 50 to 48 vote the chamber also blocked a measure by Sens. Joe Manchin III (D-W.Va.) and Patrick J. Toomey (R-Pa.) to tighten the background-check system.
All Republicans voted to block the Feinstein measure except Sen. Mark Steven Kirk of Illinois, who faces a difficult reelection campaign next year in a heavily Democratic state. On the background-check measure, Kirk, Toomey and fellow Republican Sens. John McCain of Arizona and Susan Collins of Maine voted with the Democrats.
On both measures, all Democrats were in favor except Sen. Heidi Heitkamp of North Dakota, who voted no, and Sen. Mark R. Warner of Virginia, who did not vote. A spokesman for Warner said he was unable to vote because of a prior commitment but would have supported both measures.
This fall, after a shooter at a community college in Oregon killed nine people and then shot himself, Obama directed his aides to step up efforts to get around that congressional stalemate by using his executive powers.
Since then, White House officials have been trying to draft an executive order that would reinterpret existing law to require all or most gun sales to go through the background check system.
But despite Obama's visible frustration with the lack of action, a solution has proved complicated. Many had expected the White House to announce plans for an executive order by Dec..14, the anniversary of the Sandy Hook shooting. That now seems less likely.
Requiring background checks for all weapons sales might not have had any effect on Wednesday's shootings in San Bernardino in which at least 14 people were killed. The Bureau of Alcohol, Tobacco, Firearms and Explosives has determined that Syed Rizwan Farook, one of the two shooters, legally purchased two of the weapons at a gun shop in Corona. Two others were legally purchased and given to him by a friend, federal officials said Thursday.
In most other mass shootings in recent years, the perpetrators also purchased their weapons legally through licensed firearms dealers.
Federal law requires those dealers to get federal licenses and conduct background checks on their customers. But the law offers an exemption to hobbyists, collectors and others who make "occasional sales" and are not considered to be "engaged in the business" of gun dealing.
How often such private sales take place remains unclear. One oft-cited figure suggests 40% of guns that change hands in the U.S. each year are transferred without background checks. Some of those transfers, however, are not sales, and the figure comes from a survey that is two decades old.
That lack of statistical evidence troubles those who worry about government interference with the 2nd Amendment right to bear arms.
But White House officials and their allies continue to see expanding background checks as the most promising way to prevent at least some gun deaths. While perpetrators of mass shootings have typically passed background checks, a large percentage of shooters who kill people in street violence in U.S. cities buy guns through a black market that is fueled by private sales, they say.
One option for Obama is to set a threshold for the number of guns a person would be allowed to sell without obtaining a license. Anyone selling more would automatically be deemed to be "in the business" of dealing guns and would be required to have a license and conduct background checks.
Another option would be to describe the type of sales activity that would require a seller to get a license, based on its business methods, such as record keeping, advertising and payment to employees.
"The law is very clear that those engaged in the business of dealing in guns must become licensed, but the exemption for occasional sales is confusing," said Chelsea Parsons, vice president of guns and crime policy at the Center for American Progress, which has close ties to the administration. Current regulations do not "provide sufficient guidance to individuals seeking to sell guns in compliance with the law or to law enforcement attempting to identify those who are brazenly violating it," she said.
Democratic presidential front-runner Hillary Clinton released a gun control plan in October in which she pledged to take executive action if Congress "refuses to act" to tighten the background check system.
Clinton also promised to close another gap in the system that allows a gun sale to proceed if law enforcement officials are unable to complete a background check within three days.
Supporters of that idea refer to the three-day rule as the "Charleston loophole" because it allowed a gun sale to Dylann Roof, the man accused of killing nine worshipers at a church in Charleston, S.C., in June. The same provision has been involved in other mass shootings in recent years.
Over the last couple of months, administration officials have been reviewing state and local efforts, looking for successful programs that have reduced gun violence and searching for ways to confront what they see as a scourge.
In a somber statement in the Oval Office on Thursday morning, Obama once again called on lawmakers to change the law.
"We all have a part to play," Obama said, including "legislators" in the list of those who must work to make it more difficult for violent people to get access to weapons.
"Right now, it's just too easy."
Times staff writer Lisa Mascaro contributed to this report.