Colorado's historic recall of two state legislators who backed new gun restrictions may have national repercussions, as advocates say the effort will make it harder to revive stalled efforts in Congress to tighten firearm laws.
In April, federal legislation expanding background check requirements for gun buyers fell five votes short in the Senate, despite political momentum from last December's massacre at a Connecticut elementary school.
Gun control backers say they have yet to win a single new Senate supporter, and many worry that the muscle shown by pro-gun groups and voters last week in Colorado will make it even harder to find converts.
"The NRA does its job better than our side does our job," said Jim Kessler, a co-founder of Third Way, which advocates for centrist Democratic policies. "They know how to influence and intimidate elected people."
Sen. Chris Murphy, D-Conn., who was representing Newtown, where 20 first-graders and six school staffers were gunned down, in the House at the time of the shooting, said "the results of the recall were not good news."
Minutes after the Senate rejected the new background checks on April 17, President Obama and Senate Majority Leader Harry Reid, D-Nev., pledged to continue the fight.
Democrats and gun control lobbyists, however, don't expect Reid to bring the bill up again until next year at best, not until he has found enough additional votes to have a strong chance of prevailing.
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, D-Ill., his party's 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, Colo., 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 and 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 Sens. Joe Manchin, D-W.Va., and Pat Toomey, R-Pa., seek five more votes.
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.
Participants say they have explored ways to keep the NRA neutral, including exempting gun show sales or letting buyers conduct their own background checks online. Gun control advocates objected that such concessions go too far. Participants spoke on condition of anonymity after agreeing their names wouldn't be attached to discussions of private conversations.
Asked if such changes would keep the NRA on the sidelines, Arulanandam said, "The NRA remains opposed to expanding a broken system on background checks, period." Four Democrats opposed broadening background checks: Max Baucus of Montana, Mark Begich of Alaska, Heidi Heitkamp of North Dakota and Mark Pryor of Arkansas. Others opponents wooded by advocates include GOP Sens. Kelly Ayotte of New Hampshire and Arizona's Jeff Flake.
Asked if the Colorado recalls made him less likely to switch, Flake said last week, "I was not prone to do so. I'm comfortable where I am."
The Associated Press contributed to this report