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.


0

Big spending in Ohio’s Republican Senate primary

The GOP primary for Senate in Ohio is, by leaps and bounds, the most expensive Republican primary race of the cycle — and the second-most expensive Senate primary overall this year (after California’s Senate contest). The three major Republican candidates and their allies have spent a combined $41.2 million through March 19.

The spending picture has largely been dominated by Dolan and Moreno, with LaRose, who is not personally wealthy like the other two, unable to keep pace. Dolan has spent $10.6 million on advertising while Moreno has spent $8.5 million. LaRose has not spent money on broadcast TV, cable, over-the-top/streaming or digital ads, according to data from AdImpact.

When it comes to outside spending, Dolan’s allies at the super PACs Buckeye Leadership Fund (which is largely funded by Dolan’s family) and Defend Ohio Values have spent $7 million and $1.7 million, respectively, bringing the pro-Dolan total to $19.3 million in spending.

Moreno’s supporters at the Club for Growth ($5.9 million), Buckeye Values PAC ($1.3 million) and Win It Back PAC ($823,000) — plus $3.3 million from a Democratic super PAC boosting Moreno because they believe he’ll be an easier general election opponent for Brown — bring the pro-Moreno squad’s total ad outlay to just under $20 million.

LaRose, who raised just $2.2 million through the end of February, is relying on support from his allied super PAC, Leadership for Ohio. That group has spent $5.4 million to boost his bid.

Ultimately, LaRose’s lack of access to significant personal funds hindered his ability to capitalize on the early name ID and polling advantage he had as a two-time statewide elected official. Dolan donated $9 million to his campaign out of his own pocket, and Moreno put $4.2 million of his own money into his campaign.

—Jacob Rubashkin, Inside Elections


Ohio voters are paying attention to Trump’s indictments

According to a March SurveyUSA/Ohio Northern University poll, Ohioans are keeping an eye on Trump’s various legal issues. Asked about the four criminal cases separately, at least 85 percent of respondents said they had heard about each case, and at least 62 percent said each case was “important for national politics.” The most well-known and most important case to Ohioans was the federal indictment regarding Jan. 6, which 91 percent of voters said they’d heard of and 69 percent said was important. And in all four cases, a plurality of Ohioans said they think the case should be tried before the election.

—Mary Radcliffe, 538


How much clout does Ohio’s Republican establishment still have?

It’s been a tough few years for old-guard establishment Republicans in Ohio. In the 2022 Senate primary, former state GOP chairwoman Jane Timken received a paltry 5.9 percent, even though she was endorsed by numerous GOP heavyweights, including then-incumbent Sen. Rob Portman. That same year, incumbent Gov. Mike DeWine, who is notably more moderate than many of his fellow Ohio Republicans, garnered less than 50 percent of the vote in his own primary against three challengers from the right.

While old-guard and moderate Republicans have still managed to hold onto some of the political reins of power in the state, their wins have frequently relied on support from more Democratic areas. Tonight’s Senate primary results will be an important test for them: This year, Portman and DeWine have both endorsed Dolan, while a phalanx of right-wing figures, including Trump, have thrown their weight behind Moreno. If Dolan can pull out a win, it would be a crucial victory for a group that has seemingly become an endangered species in the state.

—Cooper Burton, 538


Where are Republican women on the ballot tonight?

On the Republican side, Rep. Mary Miller is the only female incumbent on the ballot tonight. She’s uncontested in her primary and likely to hold onto her deep-red seat in the 15th District in central Illinois. Four other Illinois women are running to be the Republican nominees in deep-blue districts around Chicago. Two of them are running unopposed in the primary, but should any of them win, they’re almost certain to lose in November.

In Ohio, most of the women on the ballot face long odds to victory tonight, including Kim Georgeton, running in a crowded open race for the solidly Republican 2nd District; Elayne Cross, one of two candidates challenging 14th District incumbent Rep. Dave Joyce from the right; and Kay Rogers, a former Butler County auditor who resigned in 2008 and spent two years in prison after pleading guilty to conspiracy to commit bank and mail fraud, is taking on incumbent Rep. Warren Davidson in the 8th District.

—Monica Potts, 538


Voters in California’s 20th District may decide McCarthy’s successor today

California held its statewide primary for president and downballot races on March 5, but it still gets to join in on the March 19 fun. There’s a special election in the 20th Congressional District to fill the vacancy left by former House Speaker Kevin McCarthy, who resigned his seat at the end of 2023. The solidly red seat is all but guaranteed to elect a Republican, but the main question is whether the special will produce a winner today or necessitate a runoff.

That’s because California special elections don’t work exactly like its regular top-two primary elections. Instead, they operate similarly to Louisiana’s jungle primary system. All candidates, regardless of party, run together in a first round — the race happening today — and if one candidate wins a majority, that candidate is elected. But if no candidate wins a majority, a runoff takes place between the top two candidates. Should no one surpass 50 percent today, the two leading contenders will meet on May 21.

In some ways, the March 5 top-two primary served as a dry run for the special because the leading candidates in that race are also on the special election ballot. The favorite is probably Republican state Assemblymember Vince Fong, who led all candidates with 42 percent of the primary vote two weeks ago. Fong is viewed as McCarthy’s hand-picked successor, and he also has Trump’s endorsement. Fellow Republican Tulare County Sheriff Mike Boudreaux narrowly grabbed the second November spot with 24 percent in the primary, so he’s probably the second-most likely candidate to win or advance to a runoff. But in the primary, Boudreaux only ran a little ahead of Democrat Marisa Wood, who won 21 percent, so she could finish ahead of Boudreaux in the special. This is especially true considering that Republican turnout may not be as high today as it was on March 5 because the special won’t coincide with a much-watched GOP presidential primary.

Differences between the set of candidates running in the special and those who ran in the regular primary could also cause consequential shifts in vote share. Four minor Republicans not running in the special won about 5 percent in the primary, while a minor Democrat not running in the special won about 3 percent. Should this support line up more behind the leading contenders in each party, Fong would find himself closer to a majority to win outright, while Wood might overtake Boudreaux for the second spot in a potential runoff. Moreover, voters know how the primary result played out, so that could influence them to consolidate behind the leading candidates. Still, six other lesser candidates are on the special election ballot, so even if they don’t win much of the vote, what share they do take could still help influence the special’s outcome.

—Geoffrey Skelley, 538