Illinois and Ohio primaries 2024: Trump-backed Senate candidate prevails in Ohio primary

538 tracked key House and Senate races, including a California special election.

November’s presidential matchup may be set, but Democrats and Republicans still need to decide who will run in hundreds of downballot races (e.g., for Senate and House) this fall. A batch of these contests were decided on Tuesday, March 19.

Tuesday was primary day in Ohio and Illinois, and in the biggest contest of the day, Republicans chose former President Donald Trump's endorsee Bernie Moreno as their candidate in Ohio’s U.S. Senate race. It was a good night for other Trump endorsees too, as Derek Merrin prevailed in the GOP primary for Ohio's 9th Congressional District, while incumbent Mike Bost is leading his challenger in Illinois's 12th District, as of early Wednesday morning. Plus, a special election in California could have immediate implications for House Republicans’ razor-thin majority.

538 reporters and contributors broke down the election results as they came in with live updates, analysis and commentary. Read our full live blog below.


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ABC projects Moreno to win

ABC News has projected Moreno will win the GOP primary for Senate in Ohio, setting up a clash with three-term incumbent Sherrod Brown this fall. Moreno was endorsed by Trump, but also benefitted from spending by a Democratic super PAC that viewed him as a weaker general election opponent than the man he beat, state Sen. Matt Dolan.

—Jacob Rubashkin, Inside Elections


Trump's having a good night so far

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 AP has called for Moreno

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


Abortion may motivate Ohio Democrats

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


The GOP primary in Ohio's 9th is a mess, again

One of today's most consequential primaries for the general election is taking place in Ohio's 9th District. According to Daily Kos Elections, Trump would have carried the district 51 percent to 48 percent in 2020. But in 2022, incumbent Democratic Rep. Marcy Kaptur defeated Republican Air Force veteran J.R. Majewski 57 percent to 43 percent here thanks to Majewski's weaknesses as a candidate: He exaggerated his military service, attended the Jan. 6 rally (though he says he didn't enter the Capitol) and once subscribed to the QAnon conspiracy theory.

Majewski quickly announced he would run again in 2024, agitating Republican operatives who feared he would once again throw away a winnable House seat. But to their relief, he withdrew from the race a few weeks ago, leaving the primary to state Rep. Derek Merrin and former state Rep. Craig Riedel. Riedel was originally the top alternative to Majewski, but a couple of his pro-Trump supporters withdrew their endorsement of him after audio leaked of him calling Trump "arrogant." That sent GOP elders scrambling to find a new alternative to Majewski, and Merrin — who was in line to be the speaker of the Ohio state House last year until a faction of renegade Republicans joined Democrats to elect a different Republican — jumped into the race just before the filing deadline.

The primary is far from settled, though. While Trump endorsed Merrin just yesterday, and Speaker Mike Johnson endorsed Merrin in January, many establishment Republicans, such as House Majority Leader Steve Scalise and Majority Whip Tom Emmer, are still with Riedel. And Merrin's late entry into the race means he trails Riedel badly in fundraising, $175,000 to $1.2 million. And while he's no Majewski, a Riedel win could still give Republicans headaches: He's aligned with the tea party movement and has previously expressed interest in joining the hardline House Freedom Caucus.

—Nathaniel Rakich, 538