Although there are several gun control measures, such as universal background checks, that enjoy broad support among the general public, Congress has not enacted laws in the wake of mass shootings from Newtown to Parkland. Nor it is clear that the mass murder of 17 people on Valentine’s Day will lead to an ambitious response from Congress.

In theory, this policy stagnation in the face of widespread terror and death should be an electoral issue, with the minority party holding the majority party accountable for inaction. In practice, the Democratic Party has been reluctant to embrace gun control as a core part of its agenda, believing that gun control costs more votes than it gains in more rural districts where Democratic candidates would be competitive otherwise.

Sean McElwee argues that this is shortsighted, citing research by David Broockman and Chris Skovron showing that state legislative candidates drastically underestimate the high level of support for gun control (among other issues) in their districts.

Is this also true of the US Congress? Do national polls for gun-related proposals mask so much diversity across districts and states that gun control is a losing issue for Democrats in swing districts?

To answer this, I collected polling responses for four gun policy questions administered by the Consortium for Congressional Election Studies (CCES) in 2016. Unlike many national polls, the CCES strives to collect a sample from each congressional district. Actual samples from these questions ranged from 60 to 348 respondents, with samples of 100 to 200 in most districts. Obviously, polls from 2016 do not include any lasting shifts in public opinion resulting from the Parkland shooting and thus might understate public support for gun control. However, they do illustrate the diversity of opinion about gun control across parties and districts.

District partisanship and gun control

First, here is the percentage of respondents supporting an assault rifle ban in each House district for Democrats (blue circles) and Republicans (red triangles), with Donald Trump’s share of the two-party vote (i.e., his percentage of all Trump and Clinton votes, ignoring votes for third-party candidates) on the x-axis.

There are two obvious patterns. First, citizens support an assault rifle ban across most districts (389 of 435) within each party, so if every House Republican sided with public opinion in his or her district, the House GOP would schedule a vote on an assault weapons ban and most Republicans would vote for it.

Second, there is a lot of variation across districts with the same partisan leaning (measured in Trump’s vote share). A district that split 50-50 between Trump and Clinton might have a majority opposed to the ban, or might have 90 percent support for a ban. In this sense, support for gun control is weakly correlated with district partisanship, but there is a lot of local variation.

For comparison, the next figure shows the percentage of constituents who support proposals to “make it easier for people to obtain concealed carry permits.” Since this is a gun deregulation measure, we expect a positive relationship between Trump support and looser concealed carry laws.

Clearly, this policy proposal is unpopular in districts represented by both parties. Indeed, this proposal polled above 50 percent approval in just 61 of 435 districts. And, again, it is weakly correlated with each district’s presidential voting patterns, with a range of around 30 percent for most levels of presidential vote.

Last December, the US House passed a bill promoting one of these two policies, 231-198. If you guessed it was the popular-across-the-country assault rifle ban, well, I have a surprise for you. No, in the wake of the October mass shooting in Las Vegas, the House passed a bill allowing citizens with a concealed weapons permit in one state to carry a concealed weapon in a different state. It also sought to improve the national background check system and called for a study on bump stocks (devices that allow semiautomatic weapons to function as fully automatic ones), but the base bill was the concealed carry bill that had been waiting to come up until there was a lull in mass shootings.

Marginal members and gun control

The next three charts break House members into four groups:

Clinton-Democratic — a district with a Democratic incumbent and Hillary Clinton received most of the two-party presidential vote (181 members)

Trump-Democratic — a district with a Democratic incumbent and Donald Trump received most of the two-party presidential vote (12 members)

Clinton-Republican — a district with a Republican incumbent and Hillary Clinton received most of the two-party presidential vote (23 members)

Trump-Republican — a district with a Republican incumbent and Donald Trump received most of the two-party presidential vote (215 members)

Universal background checks

Consistent with national polls, there is universal support for universal background checks. In particular, districts represented by Republicans but won by Clinton are slightly more likely to approve of this reform than any other subgroup.

The same pattern recurs on assault weapons ban and expanding concealed carry permits: districts that elected Republicans but voted for Clinton are actually more supportive of gun control than other subgroups, and just as skeptical of gun deregulation as other Clinton districts.

Assault rifle ban

Make it easier to obtain concealed carry permits

Should Democrats campaign on gun control?

Not necessarily. The popularity of a single issue position does not necessarily translate into votes in the next campaign. Gun control is an effective campaign issue to the extent that voters supportive of gun control prioritize it, either by making support for gun control a necessary condition for their vote or by making it the decisive issue when choosing between candidates.

In other words, when gun control supporters begin to vote against (or abstain from voting for) candidates they would otherwise support on the basis of their positions on guns, then the general popularity of gun control will translate into electoral power. From this perspective, the test for the #NeverAgain movement and other gun control initiatives is not to change minds about gun control but to make the issue salient when people go the polls in November.