WASHINGTON — Gun control advocates had told themselves this time would be different. It wasn't.
The two-decade deadlock that has gripped congressional efforts to act on gun control continued Wednesday as a measure to require more gun buyers to go through background checks failed in the Senate. With it sank the legislative effort to respond to the killings of 20 first-grade children and six educators in Newtown, Conn.
The background check proposal, negotiated by Sens. Joe Manchin III (D-W.Va.) and Patrick J. Toomey (R-Pa.), won the backing of 55 senators, a majority, but fell short of the 60 needed to overcome the Senate's procedural barriers.
Seven measures came to the floor. All failed. Included were a proposal to strengthen laws against gun trafficking, two Republican measures backed by the National Rifle Assn. that would have expanded the rights of gun owners and a measure by Sen. Dianne Feinstein (D-Calif.) to ban high-capacity ammunition magazines and semiautomatic rifles considered to be "assault weapons." Feinstein's proposal lost heavily, getting only 40 "ayes."
For advocates of gun control, the vote against expanding background checks marked a bitter defeat.
President Obama, who made the issue a priority after Newtown, called the vote "a pretty shameful day for Washington" and accused the "gun lobby and its allies" of having "willfully lied about the bill."
Senators had no "coherent arguments" against the background check measure and had "caved to the pressure" from gun advocates, he said in the White House Rose Garden, flanked by family members of Newtown victims and former Rep. Gabrielle Giffords (D-Ariz.). He vowed to continue pressing for new controls.
"I see this as just round one," he said.
Feinstein decried a "lack of courage" among her colleagues. "Show some guts," she demanded in a brief speech before the vote.
But the NRA and its allies hailed the vote. The background check proposal "would have criminalized certain private transfers of firearms between honest citizens," the NRA's chief lobbyist, Chris Cox, said in a statement.
Efforts to change gun laws have repeatedly run up against an intractable divide that pits members of Congress from urban states, mostly Democrats, against those, largely Republicans, who represent more rural states with large numbers of gun owners.
After the shootings at Sandy Hook Elementary School in December, gun control advocates pointed to polls that showed overwhelming support for background checks and briefly believed that public outrage over the deaths might change that stubborn political calculus. They focused on proposals to broaden the existing law on background checks. That issue marked the "sweet spot" in the gun debate, a change that would do considerable good and was politically feasible, the gun bill's chief author, Sen. Charles E. Schumer (D-N.Y.), repeatedly said.
The current law, passed in 1993, requires people who buy guns from licensed dealers to go through a background check, but exempts sales outside that network, including those at gun shows and via the Internet. Federal officials say many sales — one study estimated 40% —bypass background checks and believe those sales are a primary source for guns used by gangs and other criminals. But optimism faded in recent weeks.
As the gun control efforts began to gain ground in the Senate, the NRA and its allies waged a highly effective campaign to rally supporters. Expanded background checks would infringe on the rights of gun owners to sell their weapons to friends or neighbors, they warned. Records of sales could one day be used to form a national gun registry, they asserted, brushing aside that federal law — as well as an explicit provision of the Manchin-Toomey proposal — bars any such effort.
"The politics never changes on this issue," said former Rep. Richard A. Gephardt (D-Mo.), who was majority leader the last time a gun bill passed Congress.
Whatever popularity gun control measures may have nationwide, a core of highly motivated voters, particularly in rural states, opposes them fervently. In the end, four Democrats from conservative states, Max Baucus of Montana, Mark Begich of Alaska, Heidi Heitkamp of North Dakota and Mark Pryor of Arkansas voted against the background check proposal. All but Heitkamp face election next year.
Asked to explain his vote, Baucus said one word: "Montana."
On the Republican side, opposition to gun control and suspicion of Obama melded to solidify opposition to new controls. When Manchin and Toomey reached their agreement last week, they discovered that few Republicans would sign on. In the end, only four, Toomey, Susan Collins of Maine, Mark Steven Kirk of Illinois and John McCain of Arizona, were willing to do so.
"It really comes down to identity politics," said Richard Feldman, president of the Independent Firearm Owners Assn., a smaller gun-rights group that backed the Manchin-Toomey proposal.
"If Barack Obama says that the sun rises in the east, well, if I'm on the other side, I know it must be false," he said, adding, in a reference to the NRA's executive vice president, "and if Wayne LaPierre says the sun rises in the west, it must be true."
In a floor speech before the vote, Manchin, who until now had an A rating from the NRA, railed against its campaign, calling its statements against his plan "a lie."
"I remember when the NRA used to feel a lot different about background checks, and it wasn't all that long ago," he said. Indeed, the gun group had proposed the instant background check system during the Clinton administration in a successful effort to head off a plan to require a waiting period for gun purchases.
McCain praised Manchin and Toomey for what he called an act of "political courage."
"You did the right thing, and it's been my experience as a senator in this body for some years who has not always done the right thing, that doing the right thing is always a reward in itself," he said. "And sooner or later this nation will take up this issue."
But Sen. Jeff Sessions, an Alabama Republican with an A+ NRA rating, rejected the idea that those on his side were acting out of improper motives.
"There's a strong feeling for the 2nd Amendment, and a strong sense that independent Americans ought to have a right to defend themselves," he said. He did not support the Manchin-Toomey plan because he opposes "more and more controls over innocent Americans and their ability to transfer a weapon," he said.
Gun control supporters vowed to continue their efforts.
"We'll return home disappointed, but not defeated," Mark Barden, the father of a Newtown victim, said as he introduced Obama at the White House. "We're not defeated, and we will not be defeated."
New York Mayor Michael R. Bloomberg, whose organization, Mayors Against Illegal Guns, spent $12 million to air television advertisements in 13 states backing the plan, called the vote "a damning indictment of the stranglehold that special interests have on Washington," and promised to work to defeat opponents of gun control in the 2014 election.
Mark Glaze, director of the mayors group, amplified that threat. "Senators who voted no to simply make the pain go away are going to be disappointed," he said. "They're going to be hearing about this every day for a very long time until they get right with their constituents — 90% of whom understand that background checks save lives and do no damage to the 2nd Amendment."
Vice President Joe Biden said the Senate "let down an awful lot of people today, including those Newtown families."
"We will prevail. If it's not tomorrow, it's not next month, the next six months, it will happen and relatively soon," he said.
Toomey, however, indicated he did not want to continue the fight. "The Senate has spoken on the subject, and it's time to move on," he said in a statement.
Senate Majority Leader Harry Reid (D-Nev.), who supported the background check proposal, changed his vote to no at the end of the roll call, a parliamentary step that allows him to move to reconsider the vote in the future. In a statement before the vote, he hinted at a possibility that many on both sides of the issue have talked about privately: that another mass shooting would put the issue before the Senate again.
Announcing that he would vote in favor of the assault weapons ban, which he had opposed earlier in his career, Reid said, "I choose to vote my conscience because if tragedy strikes again — I'm sorry to say, Mr. President, it will — if innocents are gunned down in a classroom, theater or restaurant, I would have trouble living with myself as a senator, as a husband, a father or grandfather and friend, knowing that I didn't do everything in my power to prevent that incident."
Christi Parsons and Matea Gold in the Washington bureau contributed to this report.