Exhibit A, from Public Policy Polling:
[Sen. Kelly] Ayotte now has a negative approval rating with 44% of voters giving her good marks and 46% disapproving. That's down a net 15 points from the last time we polled on her, in October, when she had a 48% approval with 35% disapproving. 75% of New Hampshire voters- including 95% of Democrats, 74% of independents, and 56% of Republicans- say they support background checks
Exhibit B, from Quinnipiac:
Pennsylvania voters approve 34 - 29 percent of the way U.S. Sen. Pat Toomey is handling gun control and give Sen. Toomey an overall 48 - 30 percent approval rating, his highest ever. By a 54 - 12 percent margin, voters think more favorably of Toomey because of his co-sponsorship of legislation to require expanded background checks.
So: if you're from a state that went for Barack Obama, even narrowly, the evidence suggests that you should at least be seen as supporting "background checks." The president won both states by 10 points in 2008, and both by 5 in 2012.
This really underscores how politically useless the final vote -- the failed amendment vote, the one that required 60 ayes -- was for the White House. Only a few of the Republicans who voted no are from states carried by the president. Only a few are up for re-election in 2014. In the House, there are around 15 Republicans from districts carried by the president, and of course every member is up for re-election next year. But the bill never got to the House. Nobody's testing the hold-outs; nobody's able to prove whether real heat comes your way if you're from that turf and you cross Gabby Giffords.