Let's check in on how Trump's three endorsed candidates are doing tonight! As it turns out, all three are currently leading their races (though we're just now getting the very first results from Illinois's 12th District, so take that one with a grain or ten of salt).

—Jacob Rubashkin, Inside Elections

The Associated Press has called the GOP Senate primary in Ohio for Moreno, though ABC News has not yet made a projection. He currently leads with about 42 percent of the vote, and 25 percent of the expected vote reporting.

—Jacob Rubashkin, Inside Elections

Cooper, I wonder how much the potential threat of limiting abortion access in Ohio could impact that Supreme Court race. In 2023, voters in the state passed a constitutional amendment protecting abortion access. In a sign that abortion may continue to be an issue that divides Republican-leaning voters, a November Emerson College/WJW-TV/Nexstar survey conducted just after that election asked registered Ohio voters how they voted on the abortion measure and how they plan to vote in November this year.

Twenty-six percent of those who voted to pass the abortion rights measure said they plan to vote for Donald Trump, suggesting that a fair number of Republican or Republican-leaning voters supported it. (In comparison, just 10 percent of those who voted against the measure said they planned to vote for Joe Biden.) Abortion also seemed to drive turnout among Democratic-leaning voters in last November's election: Among those that said they voted on the abortion referendum (either for or against), 41 percent said they'd vote for Biden, while only 28 percent of those who didn't vote supported Biden. (About half of both 2023 voters and nonvoters supported Trump.)

So if the issue of abortion becomes salient in the state Supreme Court race, there could be a close race coming our way in November.

—Mary Radcliffe, 538

With 34 percent of the expected vote in, incumbent Davis is well in the lead with 53 percent of the vote so far. His two top challengers, Conyears-Ervin and Collins, are nearly even for second place with 21 percent and 18 percent of the vote, respectively. Four Democrats ran in the primary against Davis in this deep blue district that includes parts of Chicago's west side; Davis has held the seat for 28 years. Collins has run to his left twice before and has been endorsed by progressive groups.

—Monica Potts, 538

Democrats (and allied independents) currently hold a bare majority in the U.S. Senate, with 51 seats to Republicans’ 49. But control of the chamber is at stake in November, and the Senate race in Ohio is one of a few competitive contests that could decide control of the chamber.

Three Republican contenders are facing off today for a chance to challenge incumbent Democrat Sherrod Brown in that contest: Matt Dolan, a state legislator running with the endorsement of former Ohio Sen. Rob Portman; Frank LaRose, the current Ohio Secretary of State running on a campaign of conservatism and electability; and Bernie Moreno, a businessman with endorsements from Trump, a dozen members of Congress including Ohio Sen. J.D. Vance and the Club for Growth PAC, one of the oldest conservative PACs in the country.

Moreno, who appeared alongside Trump in several campaign events this past weekend, has gained significant ground in the polls since the former president endorsed him in mid-December. Then, he was polling at 16 percent in 538’s polling average — and now he’s hovering in the mid- to-high-20s. Democrats view Moreno as the weakest candidate for the general election and last week began airing a television ad intended to boost his standing by “attacking” his conservative record and support for Trump ahead of Tuesday's primary.

But the polls show a tied race between Dolan and Moreno, who each lead LaRose by 10 percentage points. That’s too close for polls to provide a reliable signal of who is decisively leading: Per our database of historical polls, surveys of Senate primaries miss the margin between the winner and runner-up by 6.5 points on average.

Looking ahead to the general election, the winner of today’s Republican primary matters not just in deciding who might be Ohio’s next senator, but in deciding control of the Senate come 2025. Since West Virginia Democratic Sen. Joe Manchin decided to retire, prognosticators largely expect the Republicans to pick up at least one seat this November. That means Democrats and Republicans start their fight for the majority from a 50-50 tie, and Democrats need to at least hold on to the rest of their endangered seats — and for Biden to win — to maintain control.

Ohio is a red state, but Brown has managed to run ahead of expectations in previous cycles. So has fellow endangered Democrat, Montana Sen. Jon Tester. But neither of them have run in a presidential cycle since 2012, when President Barack Obama pulled off a surprising reelection and Democrats gained two seats in the Senate. Brown will face not just the strength of his opponent in November, but the partisanship of his constituents. The Cook Political Report rates the Ohio Senate race a toss-up.

—G. Elliott Morris, 538