“We’re going to make this a voting issue just like the other side does,” she said. That’s a more succinct distillation of something President Obama said after the Umpqua Community College shooting. “I’d ask the American people to think about how they can get our government to change these laws, and to save lives, and to let young people grow up,” he said. “If you think this is a problem, then you should expect your elected officials to reflect your views.”

What would that kind of shift take?

In fact, it’s already the case that there are a good number of Americans who treat gun control as a central litmus test for political candidates. In a Gallup poll in October, 21 percent of voters said they would only vote for an office-seeker who sought stricter gun laws. Another 59 percent said stricter gun laws were one of several issues important to them. That’s a pretty big group.

On the other hand, twice as many people who support looser gun laws—40 percent—say they will only vote for a candidate who agrees with them.

Even if Clinton were able to double the number of single-issue pro-gun-control voters, it might not make any real dent in the nation’s gun laws. In part, that’s because Democrats tend to cluster in cities, where elected officeholders are already more likely to favor gun control. It’s also in part because the barriers to gun control don’t involve lack of rank-and-file political support—as Waldman’s 90 percent statistic attests. More important are things like conservatives’ distrust of liberals to enact modest controls that they agree with, and savvy lobbying work by the NRA. In the Democratic primary, however, that may be beside the point.