The rumors were true: House Speaker Paul Ryan is retiring from Congress. One of the most powerful political jobs in the United States will change hands next year, which will surely have a major effect on how the country is governed, but we’re here to discuss something slightly less weighty: the effect Ryan’s departure will have on his district — and the House of Representatives — this November.

Ryan’s national stature makes it easy to forget that he’s also the representative for Wisconsin’s 1st Congressional District, which stretches from his native Janesville in south-central Wisconsin to Racine and Kenosha on the Lake Michigan shore. The area is moderately to solidly Republican: No Democrat has won the district in a partisan statewide race since at least 2010, which is as far back as data for the district goes, and Ryan defeated his last two Democratic challengers there with 65 percent (2016) and 63 percent (2014) of the vote. However, Ryan (with his monster fundraising skills) was an incredibly strong incumbent, and the district is likely to be much more competitive without him on the ballot.

According to Daily Kos Elections, President Trump won the district 53 to 42 percent in 2016, while Mitt Romney carried it 52 to 47 percent in 2012. Going by FiveThirtyEight’s preferred calculation for a district’s partisan lean, the Wisconsin 1st is 11.3 percentage points more Republican than the nation as a whole. (For reference, the median House district is about 5 points more Republican than the country as a whole.) In a normal year, that means the Republican nominee should hold the seat easily. But 2018 isn’t shaping up to be a normal year: A sizable Democratic wave appears to be building that could be enough to overcome an 11-point handicap. Currently, the FiveThirtyEight generic-ballot tracker suggests Democrats will win the House popular vote by almost 7 percentage points; if Ryan’s district swings about 7 points toward Democrats in a reflection of the national mood, that could produce a close race for his old seat. Since Trump’s inauguration, Democrats in special elections have overcome far more daunting disadvantages.

Taken together, the combination of a potential Democratic wave and the fact that no incumbent will be running have put this district within reach for Democrats. Nonpartisan election handicappers such as Inside Elections and the Cook Political Report are already reflecting this new reality by moving the Wisconsin 1st from the “Solid Republican” category to “Lean Republican.”

But we still don’t know who will be in the race. Democrats have been excited about their chances here for a while thanks to internet sensation Randy Bryce, better known by his Twitter handle: “Iron Stache.” The Ron Swanson-esque ironworker had parlayed a viral launch video into a prodigious $2.3 million war chest as of the end of March, but he has also drawn criticism for being behind in his child-support payments, sending ill-advised tweets, and spending campaign money in questionable ways. Janesville school board member Cathy Myers is also seeking the Democratic nomination, and today’s news could embolden other Democrats to jump in as well.

For their part, Republicans have a deep bench in the district, which is home to no fewer than three Republican state senators and 10 Republican state representatives, according to RRH Elections, a conservative blog. Early GOP buzz has focused on state Assembly Speaker Robin Vos and University of Wisconsin Regent Bryan Steil.

Though Ryan’s retirement may only directly cost the GOP one seat (if that), it’s also a symbolic blow to Republicans’ battle for House control. According to CNN’s House retirement tracker, 38 House Republicans, including Ryan, are not running for re-election this year, and 25 of them are retiring from politics completely (as opposed to running for higher office). That’s the most since World War II, according to the Brookings Institution. It also contrasts sharply with Democrats’ retirement numbers (17 open seats, nine outright retirements). That’s not the most reassuring set of numbers for Republicans, but a high number of retirements for one party doesn’t necessarily signal that that party will suffer huge losses in the following election. Instead, retirements can be an accurate reflector of how poor those incumbents perceive their electoral fortunes to be.

If Ryan’s decision in turn spurs more retirements — say, among his closest allies in the House or among Republicans in similarly borderline-competitive districts — Republican gloom and doom could become a self-fulfilling prophecy. The advantages of incumbency may be shrinking, but they’re still very real. Every Republican retirement makes it a little bit harder, a little bit more expensive for the GOP to hold onto that seat — Ryan’s included.