That means the Dec. 14 anniversary of the school shootings probably will pass without a fresh Senate vote. Some gun curb advocates have hoped to use the widespread public attention that anniversary will receive to schedule a new vote by then.
"My advice to Reid is, if there's any indication of change or movement in a positive direction, we should consider it. But so far I've not seen that," said Sen. Dick Durbin, the Democrats' chief Senate vote-counter.
Colorado voters last Tuesday removed two Democratic state lawmakers from office Senate President John Morse and Sen. Angela Giron and replaced them with Republicans who are gun-rights supporters.
The two Democrats had supported expanded background checks and limits on ammunition magazines. Colorado enacted those measures following Newtown and a July 2012 rampage in an Aurora, Colorado, movie theater that left 12 dead and 70 wounded.
The recall drew national attention and became a proxy fight between gun control and gun rights forces. New York City Mayor Michael Bloomberg, an advocate for stricter gun laws with his group Mayor's Against Illegal Guns, contributed around $350,000 to the two Democrats. The NRA spent roughly the same amount opposing them.
Overall, reported contributions to Morse and Giron totaled around $3 million, giving them a 5-1 advantage over recall supporters. Yet foes of the two state senators found enough angry voters to prevail.
NRA spokesman Andrew Arulanandam played down his group's role. He noted the overall spending disparity, saying his organization participated only after being asked to by local gun-rights advocates.
"It sends a strong message that grassroots still matters, and voters trump Bloomberg and his money," he said of the vote, echoing a theme the NRA has used before against the wealthy New Yorker.
Mark Glaze, executive director of Mayors Against Illegal Guns, said the NRA "cherry-picked" two vulnerable legislators to target. He said his group's spending in those races underscored its commitment.
"Legislators who take risks to keep the public safe are going to have every resource they'd ask for to defend themselves," he said.
Former Colorado Gov. Bill Ritter, a Democrat, said his state's recall votes meant little for U.S. senators pondering their stance on guns. He said the recall movement tapped into public unease with a broad Democratic agenda "that may have drifted too far to the left," including enactment of civil unions for gay and lesbian couples and in-state tuition for college students in the U.S. illegally.
Murphy and other gun control supporters such as Dan Gross, president of the Brady Campaign to Prevent Gun Violence, say that with polls showing wide approval of background checks and groups like Bloomberg's spending large sums, the NRA's potency has been weakened.
Even so, Senate talks have proceeded intermittently as supporters of the background check language written by Democratic Sen. Joe Manchin of West Virginia and Republican Pat Toomey of Pennsylvania seek five more votes.
A majority of senators voted in favor of expanding background checks, but the measure fell short of the 60 votes needed under Senate rules to advance the legislation.
Background checks, aimed at weeding out criminals and the mentally unstable, are required for buyers obtaining firearms through licensed gun dealers. The defeated legislation would have expanded that to sales at commercial venues like gun shows and the Internet.
