Why is today’s special election in Georgia’s 6th Congressional District important? It’s just one race for one House seat, but as my colleague Nate Silver wrote on Monday:

Sometimes dumb things matter if everyone agrees that they matter. Congressional Republicans could use a signal of any kind right now to coordinate their strategy around two vexing issues: first, their health care bill, and second, their behavior toward President Trump and the investigations surrounding him.

That’s all true, but I’d also argue that the election in Georgia 6 is a bit more interesting than your average House race because it’ll give us a good reading on how a crucial bloc of voters are feeling about things five months into the Trump era.

President Trump won the 2016 election because he was able to win a sizable share of voters who didn’t like him. Most of these voters cast a ballot for him because they didn’t like Hillary Clinton either, but they represent the most winnable slice of Trump backers for Democrats going into the 2018 midterms. That’s why FiveThirtyEight, along with SurveyMonkey, has been tracking the opinions of these “reluctant” Trump voters since Trump took office. They make up about 7 percent of all voters, which may not seem like a lot, but even if only half of them shift into the Democratic column in 2018, Democrats could take back the House.

And that brings us back to Georgia 6: It’s a reluctant Trump district. If Democrat Jon Ossoff can win in Georgia 6 over Republican Karen Handel, it could be a sign that Democrats can win over reluctant Trump voters nationwide next year.

Chip Lake, a GOP political strategist in the Peach State, summed things up nicely for Politico: “If we’re losing upper middle-class, suburban seats in the South to a 30-year-old progressive liberal, we would be foolish not to be deeply concerned about the possibility that would exist for a tidal wave election for Democrats in 2018.”

Nationally, reluctant Trump voters differ from other Trump supporters in three important ways. We don’t have polling on reluctant Trump voters in Georgia 6 specifically, but what we do know about the district suggests that Trump voters in Georgia 6 disproportionately fall into the reluctant bucket.

Demographics

Reluctant Trump voters, on average, have more education than other Trump voters; it’s one of their defining features as a group. According to SurveyMonkey, 37 percent of reluctant Trump voters have at least a college degree compared with 25 percent of other Trump voters. That matches with the general movement away from the Republican Party by well-educated voters in 2016.

The latest American Community Survey finds that 58 percent of Georgia 6 residents 25 and older have at least a college degree, which is higher than all but five other congressional districts in the nation. Among Trump voters who are expected to cast a ballot in Tuesday’s special election, education levels are even higher. A recent Atlanta Journal Constitution poll of likely special-election voters determined that an astounding 81 percent of people who said they voted for Trump had at least a college degree. If Democrats are going to continue to make inroads among well-educated voters in 2018, we should see signs of those gains in Georgia 6.

Politics

Not to put too fine a point on it, but reluctant Trump voters are less invested in Trump than his more enthusiastic supporters. Just a few months into Trump’s term, they were far more likely to prefer a different Republican be president; SurveyMonkey found that just 26 percent of reluctant Trump voters, compared with 77 percent of other Trump voters, would choose Trump as their president in a hypothetical matchup against Vice President Mike Pence and Ohio Gov. John Kasich. Given that more districts lean Republican than Democratic nationally, Democrats are going to need to make inroads among traditionally Republican voters such as those in Georgia 6, which hasn’t elected a Democratic representative since before Newt Gingrich represented the district.

Trump voters in Georgia 6 are also probably more loyal to the Republican brand than to Trump specifically. In the Atlanta Journal Constitution survey, only 35 percent of people who voted for Trump in 2016 say their vote in the special election is meant to express support for Trump now. (On the other hand, 75 percent of Clinton voters say their vote in the special election is meant to express opposition to Trump now.) That shouldn’t be too surprising because Republican voters in Georgia 6 preferred a different candidate in the 2016 primaries. Trump lost Georgia 6 to Marco Rubio by 11 percentage points. That’s amazing considering that outside of the home states of Trump’s major primary competitors (Florida, Ohio and Texas) Trump lost just 55 (or 18 percent) of the congressional districts in caucuses and primaries for which we have data. If GOP voters are going to apply a Trump penalty to Republican House candidates in red districts in 2018, we should see something similar happen in Georgia 6.

Issues

Reluctant Trump voters are more likely to believe that health care is a top concern than Trump’s more enthusiastic supporters. In our June poll with SurveyMonkey, voters were asked which issue mattered most to them right now. Overall, 21 percent of reluctant Trump voters said health care (the second-highest issue after “jobs and the economy.” Among other Trump supporters, it ranked third at 15 percent, after the economy and terrorism. Democrats, of course, want to run on the issue of health care and hope the American Health Care Act’s unpopularity will catapult them to victory in 2018.

A SurveyUSA poll conducted over the last week found that Georgia 6 Trump voters also had health care as a top concern. Although the question was somewhat different from the version asked by SurveyMonkey, 31 percent of Trump voters in Georgia 6 listed health care as the most important issue to their vote. As with reluctant Trump voters nationwide, it was Trump voters’ second-most important issue in the district. Indeed, Ossoff and Handel had one of their most contentious debate moments over health care. Ossoff went after the House Republican bill, while Handel defended it. If Democratic attacks on the Republican health care bill are going to work nationally to move traditionally Republican voters into the Democratic column, you’d think it’d need to work in Georgia 6.

Ossoff might win the Georgia 6 House special election, and Democrats could fail to retake the House next year. Or, Handel might win and Republicans could lose the chamber in 2018. It’s just one data point, after all. That said, it’s a pretty useful data point. It’ll give us a good idea about how Trump’s most unenthusiastic backers are feeling. It’ll also provide us clues as to how traditionally Republican voters who moved against Trump last year and who seem to be willing to abandon him in even larger numbers in 2017 are going to vote in 2018. If Democrats cannot win here, it suggests that they may need a different roadmap for taking back the House than going after reluctant Trump voters.