In Illinois' 12th District, Bost is ahead of challenger Bailey by 10 percentage points, 55 to 45 percent, with 36 percent of the expected vote in. But there's still a lot of vote to be counted in the eastern part of the district, where Bailey is stronger.

—Jacob Rubashkin, Inside Elections

In Cuyahoga County, Ohio, home to Cleveland, incumbent Prosecutor Michael O'Malley is fending off a strong challenger from the left, former public defender Matthew Ahn. O'Malley has been criticized for a string of wrongful convictions and death sentences, but currently leads Ahn 64 to 36 percent, with 20 percent of ballot scanners in the county reporting, according to the Cuyahoga County Board of Elections.

—Cooper Burton, 538

For those of you who aren't familiar with Derek Myers, the 31-year-old who accidentally sent out a concession statement several hours before polls closed, you're in for a real treat. The Cincinnati Enquirer recently wrote a pretty comprehensive expose into his past legal troubles, which is definitely worth reading (especially given that Myers has filed a libel suit against the paper).

Also worth reading is Myers' response to the reporters who wrote the article, which the Enquirer published in full and which included such gems as when Myers says he once told a deputy who pulled him over for speeding that he "was not trained enough to handle someone of Derek's caliber," and later tells the reporter, "you are playing in dangerous waters, my little friend."

If that's not enough for you, Myers previously made news last year for his brief stint working for embattled New York Rep. George Santos, who he accused of sexual harassment.

—Jacob Rubashkin, Inside Elections

In Ohio's 15th District, Zerqa Abid, an anti-violence and anti-gang advocate in the Columbus area, is projected to lose her primary against former state Rep. Adam Miller, according to ABC News. Miller will face Republican incumbent Mike Carey in the fall. The district is fairly safely Republican, and Carey received Trump's endorsement when he first ran in an open special primary in 2021.

In all, 13 of the 17 Democratic women running tonight are projected to win their primaries, including nine incumbents.

—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