Polls have now closed across Illinois, where we'll be monitoring several U.S. House primaries, as well as a closely-watched referendum in Chicago. Rep. Mike Bost is facing a challenge from his right, while Rep. Danny Davis is facing one from his left.

—Cooper Burton, 538

The first votes for Ohio's 9th Congressional District are rolling in, and with 13 percent of the expected vote reporting, Merrin is slightly ahead with 46 percent of the vote, while Riedel is second with 39 percent, and Lankeneau is a distant third (14 percent). As Nathaniel wrote earlier, Merrin was a late addition to the contentious race after audio leaked of Riedel calling Trump "arrogant." And as I wrote earlier, Merrin is no stranger to intra-Republican battles.

—Monica Potts, 538

As we wait for the first results to trickle in, let's take a look at the issues voters are thinking about in the state. Among likely primary voters in Ohio, Republicans are much more concerned about immigration than Democrats, according to a poll released last week by Emerson College/The Hill/Nexstar. Specifically, given a list of options, 27 percent of voters who said they were very likely to vote in the Republican primary selected "immigration" as the most important issue facing Ohio, while only 2 percent of very likely Democratic primary voters said the same.

Republican primary voters were also more likely than Democratic primary voters to name "the economy (jobs, inflation, taxes)" as the most important issue facing the state, 39 percent to 27 percent. On the flip side, likely Democratic primary voters were more likely than Republicans to select "abortion access," 15 percent to 3 percent, and "threats to democracy," 18 percent to 7 percent.

—Mary Radcliffe, 538

Polls have now closed across Ohio. The Buckeye State usually counts its early and mail votes first, so expect to see some large vote dumps right off the bat. A word of caution, though: Early and absentee votes are not necessarily representative of the electorate as a whole. We'll want to wait to get more Election Day votes in before drawing any concrete conclusions.

—Cooper Burton, 538

As Geoffrey mentioned, Fong is the front-runner in today's California 20th special election, and there's a chance he wins the seat outright today if he gets a majority of the vote. Other than Fong, perhaps no one is rooting for this outcome more than House Speaker Mike Johnson, whose Republican majority is currently paper-thin — and getting thinner.

Right now, the House has 219 Republicans and 213 Democrats, meaning Johnson can afford two Republican defections to pass legislation with a bare majority (three Republican defections would yield a 216-216 tie, which isn't enough to pass a bill). However, GOP Rep. Ken Buck recently announced that he would resign on March 22, which will bring the GOP majority down to 218-213.

If Fong wins outright today, he would presumably be sworn in around the same time that Buck leaves, keeping the Republican majority at 219-213. But if he doesn't, the soonest Fong (or another resident of the California 20th) could take office would be late May following a runoff. And in fact, an April 30 special election in New York's 26th District is very likely to send a Democrat to Congress, which would narrow the GOP majority to 218-214 if the California seat is still vacant. That would mean that, for a time, Johnson could only afford one Republican defection before his bills would fail! If you thought it was hard for House Republicans to govern before …

—Nathaniel Rakich, 538