The New Republic's Alec MacGillis examines whether changing attitudes about gun violence present an opening for groups such as New York Mayor Michael Bloomberg's Mayors Against Illegal Guns and Gabby Giffords and Mark Kelly's Americans for Responsible Solutions:

The NRA, of course, has real clout. Like many other groups, it lobbies in Washington and state capitals, buys ads and deploys activists during elections, and maintains a ratings system that grades elected officials and candidates on their support for its goals. What sets the NRA apart is its relentless invocation of the Second Amendment, the single-mindedness of its supporters, and the inchoate nature of its hold on politicians. Its approval has come to signify not merely support for gun ownership, but American authenticity. For many in Congress, it’s “a cultural thing,” says one veteran Senate staffer. “You have to pass a cultural test for [constituents] to listen to you on the other stuff.”

And yet for some time now, the NRA’s power has been more a matter of entrenched wisdom than actual fact. Gun ownership is declining—from half of households in the 1970s to a third today. A slew of senators and governors have won campaigns in red or purple states despite NRA F ratings, including Tim Kaine (Virginia), Kay Hagan (North Carolina), Sherrod Brown (Ohio), Claire McCaskill (Missouri), and Bill Nelson (Florida), who has campaigned on gun control but has won majorities even in deeply conservative Panhandle counties. Senator Chris Murphy, a rookie Connecticut Democrat who has taken a lead on the issue since the Newtown massacre, points out that, of the 16 Senate races the NRA participated in last year, 13 of its candidates lost. “The NRA is just all mythology,” he says. “The NRA does not win elections anymore.”