Gun violence “is something we should politicize,” President Barack Obama insisted in emotional, frustrated remarks on Thursday after a mass shooting at Umpqua Community College in Roseburg, Oregon left ten people dead.

Obama’s speech charged politicians to lead with gun control legislation, but he left out the more obvious point: Congress’s makeup needs to change if there’s any hope of ever passing the most basic of gun control legislation, universal background checks. This starts with targeting vulnerable pro-gun politicians and replacing them with Democrats or Republicans who better represent public opinion.

And no one is more vulnerable than Senator Kelly Ayotte of New Hampshire, who faces reelection in a presidential swing state in 2016.

Ayotte is an incumbent of an unpopular Congress in a blue-leaning state. No matter what, she'd already face an uphill climb during a presidential year, when turnout is generally better for Democrats. But it's her record on gun violence that could tip the scale in favor of Democrats.

After the Newtown, Conneticut shooting in late 2012, Ayotte was considered a possible GOP vote in favor of the Toomey-Manchin amendment to strengthen background checks. In the end, only four Republicans broke with their party to vote for the bill, leaving it to fail 54-46 in the Senate. Ayotte was one of the votes against it. For weeks after her vote, Ayotte faced tough questions at town halls over her vote, including one memorable encounter with the daughter of a Newtown victim. "You had mentioned that the burden to owners of gun stores that these expanded background checks would cause," the daughter Erica Lafferty said. "I'm just wondering why the burden of my mother being gunned down in the hall of her elementary school isn't as important as that?" Ayotte's poll numbers fell. According to an April 2013 survey by the left-leaning Public Policy Polling, before the vote, 48 percent of New Hampshire voters approved of the job she was doing, while 35 percent disapproved. After the vote, she went underwater, with 44 percent approving while 46 percent disapproved. Since then, she's recovered her poll numbers.