There will almost certainly be an aspect of the National Rifle Association's convention — which opens today in Houston — that feels like a victory celebration. By organizing and agitating its members, the organization was able to kill a Senate compromise on background checks, steamrolling over an ineffectual Organizing For Action. But as discussion of reviving that deal heats up, the NRA may finally face a real roadblock: public opinion.

Prior to the April 17th vote — which failed to end a Republican-led filibuster on a bipartisan compromise to expand background checks — there were certainly coordinated organizing efforts. Mayors Against Illegal Guns, Michael Bloomberg's group, launched a series of ads targeting wavering senators. (The group will also be outside the NRA convention today with survivors of gun violence.) The general expectation was that such efforts would be complemented by the sort of grass-roots push for which the Obama campaign — and, by extension, the evolutionary Organizing For Action — was known.

That didn't happen. Politico has an underwhelming review of OFA's efforts leading up to the vote, the sort of key priority of the president's that the group was designed to push. In short, OFA was a non-factor.

Built on the neighbor-to-neighbor model that helped win two presidential campaigns, OFA at first consisted of professional staff based in Chicago and Washington directing volunteers while retaining control over the message, outreach and Obama’s vaunted e-mail list. But the limits of the all-volunteer army quickly became apparent: even ardent Obama fans couldn’t make a strong push for him on the off-time from their regular jobs, and they didn’t have the resources to mount the kind of field or messaging operation that made the 2012 such a juggernaut.

Politico points to key people in states where Democratic senators voted to kill the compromise. In North Dakota, one was busy working at a car dealership. In Montana, the lack of a gas reimbursement kept an organizer from prowling the rural state. In Alaska, Obama's former state director said simply, "I haven’t heard of anyone who is interested" in volunteering. OFA's promise to punish senators who balked has been similarly fruitless.

The gun lobby's victory on background checks has sparked some spontaneous energy, similar to the massive outpouring following California's 2008 vote to block gay marriage. At an event on Tuesday — at which, Politico notes, there was "no discernible OFA presence" — Senator Kelly Ayotte of New Hampshire was confronted by a furious mother from Newtown. Ayotte is still under pressure, but last night, an inverse of that scene played out in Tucson, as Slate's Dave Weigel reported.

McCain called on a woman named Pam Simon.

"I would like to thank you so much for your vote on background checks," said Simon.

There was loud, sustained applause.

Simon, a former staffer for Gabby Giffords, was shot through the arm by Jared Loughner in the 2011 shooting in Tucson. She presented McCain, one of four Republican senators that voted for the compromise, with a bouquet of 19 roses after the event — one for each person killed or injured by Loughner.

The most threatening response to the NRA in the wake of its victory has been an informal one, sparked by polls from Public Policy Polling. We've written about their polls showing the political hit taken by those who opposed the compromise, and the effect the left-leaning, headline-hunting, typically accurate group has had on Jeff Flake, apparently the most unpopular Senator in America after his gun vote. But another set of polls shows that two Democrats in red or swing states saw a boost from backing the background check policy. PPP reports that 44 percent of Louisiana voters said Senator Mary Landrieu's vote for the policy made them more likely to support her — including a plurality of independents. For North Carolina's Kay Hagan, 52 percent of all voters were similarly inclined; 59 percent of Republicans are either more likely to support Hagan now or said the vote didn't matter.

These surveys have been hailed as the sort of evidence that OFA has been unable to provide: there is a political cost to opposing background checks, a policy still supported by more than three-quarters of Americans. Flake, one of the senators PPP suggested had taken a hit, says that the questions were skewed to make him look bad — a line that will almost certainly be echoed by the NRA during its convention, which will feature Senator Ted Cruz, Sarah Palin, and the gun lobby's new president, among others.. The NRA clearly recognizes the threat these polls pose, as evidenced by its effort to provide air support for its allies. Meaning that, after all of these months, the sleeping giant of public opinion is finally being brought to bear on the background check fight, even as it carries on.