Ohio was a test case for 2024. The GOP establishment looks screwed.

The conventional view of J.D. Vance’s victory in Ohio’s Senate primary this week was that it demonstrated the power of Donald Trump’s endorsement.

But the election results also delivered something else: an outline of the 2024 GOP primary’s establishment lane, the one expected to be occupied by the likes of Govs. Asa Hutchinson of Arkansas or Larry Hogan of Maryland, former Gov. Chris Christie of New Jersey or someone else from the party’s traditionalist wing.

In a crowded contest in which a field of free-spending Republicans competed for the Trump vote, the performance of the one serious contender who distanced himself from the former president proved revealing.

State Sen. Matt Dolan, a conservative who accused Trump of “perpetuat[ing] lies about the outcome” of the 2020 election yet declined to be characterized as a Never Trumper, managed to exceed expectations and rise in the polls. But it wasn’t enough — not for first or even second place.

Still, in finishing third with 23 percent, Dolan managed to provide some clues to the size and composition of a key voting bloc in the next presidential primary — signs that suggest the Herculean task ahead for GOP institutionalists.

“It’s a MAGA-MAGA party,” said former Illinois Rep. Joe Walsh, who unsuccessfully challenged Trump for the Republican presidential nomination in 2020. “Trump’s going to run. But let’s assume he didn’t. You’d have seven to eight MAGA candidates, and maybe you’d have one Larry Hogan or something like that. But they’re not going to get any traction.”

The lesson from Ohio, Walsh said, is that “there’s no room for that, certainly not a winning lane. And if you’re a Trump critic, you won’t even register.”

For anti-Trump Republicans, the unlikely, best-case scenario for 2024 had always been that Trump would fade or not run for president again and a raft of MAGA hardliners would rush in to claim his mantle, splitting up the base and allowing one establishment-oriented Republican to slip past them in the early nominating states.

It’s a reversal of what Trump did to a crowd of institutionalists in the earliest stages of the 2016 primary.

But Ohio was Exhibit A in how difficult that will be in 2024.

Dolan, whose family owns Cleveland’s Major League Baseball franchise, was about as close to a perfect test case for a credible MAGA alternative as you could find. He was less toxic to base Republicans than a never-Trumper, having voted twice for the former president. Rather, Dolan was an “enough-with-Trumper,” said Mark Weaver, a Republican strategist and former deputy attorney general of Ohio who advised Dolan on a previous campaign.

Dolan had money — he spent more than $10 million out of his own pocket on the race — and name recognition. And among Republican politicians betting on “an appetite for something that does not involve wearing a red hat,” Weaver said, Dolan had the lane largely to himself.

The problem for Dolan — and for any 2024 hopeful of the same mold — is that lane was nowhere near wide enough.

Dolan won Ohio’s two most populous counties, Franklin and Cuyahoga, home of Columbus and Cleveland and their suburbs. He finished second in Cincinnati’s Hamilton County. But Dolan was unable to run up the score as significantly as his campaign expected even in those urban and suburban areas, an adviser said.

And he was blown out nearly everywhere else. In some rural parts of the state, Dolan finished in single digits.

“If you look on the spectrum of support for Dolan, his highest level of support came from people who are the least supportive of Trump — a small number of people,” said Tony Fabrizio, Trump’s 2020 pollster.

In 2024, he said, “There isn’t a lot of room in that lane. … It’s not big enough to support one [candidate], never mind four or five.”

Dolan’s performance in Ohio was reminiscent of — though less successful than — John Kasich’s in the 2016 Ohio presidential primary. Then Ohio’s governor and ever since a vocal Trump critic, Kasich, like Dolan, performed best in more urban and suburban, heavily populated areas of the state. At the time, it was enough for Kasich to win his home state.

But that was it. Ohio was the only primary Kasich won. And after Trump became president — pulling the party closer to him than it was in 2016 — Kasich learned his lesson, saying there was “no path” to the White House for him in 2020.

The landscape is even bleaker for a Trump-critical Republican today, even if Trump is no longer the incumbent. Given the party’s Trump-ian composition, said Jeff Sadosky, a former adviser to retiring Sen. Rob Portman (R-Ohio) and Ohio Gov. Mike DeWine, “I don’t think [Kasich would] have gotten double digits.”

“The party has changed,” Sadosky said. “I think you can be successful without embracing Trump, but it remains very challenging to get through a Republican primary when you are openly anti-Trump.”

One Republican strategist in Ohio described Dolan’s performance as evidence that “there’s a quarter of the party that’s ready to move on [from Trump].”

“Is that going to be enough [in 2024]?” the strategist asked. “I really don’t know. As of Tuesday, it wasn’t enough. But as we get further and further away from 2020, the fever may start breaking.”

Still, the strategist said, “There’s not a lane for like a [Mitt] Romney-type statesman.”

Trump-ism will take some hits this summer. In Georgia and Idaho, two incumbent Republican governors are running ahead of Trump-supported challengers, and Trump-backed candidates are involved in close contests in other states that might raise questions about the strength of his grip on the party.

Even in Ohio, Trump’s endorsed candidate, Vance, won the primary with only 32 percent of the vote. In an op-ed in The Wall Street Journal widely shared by establishment Republicans after the election, the Republican strategist Karl Rove noted “almost 68% of Ohio Republicans ignored or rejected the former president’s call to join in his ‘Complete and Total Endorsement’ of Mr. Vance.”

It’s possible Dolan would have performed better in Ohio if the field was larger — on the scale of an open presidential primary. In a wide-open contest in 2024, a candidate could carry early primary states with a small proportion of the vote. In 2016, Trump finished second in Iowa, then first in New Hampshire and South Carolina, but only with about a third of the vote. Had establishment candidates not chopped up the rest of the party’s support, Trump might have stalled.

“A moderate Republican absolutely has a chance in a large field,” said Mike Dennehy, a former executive director of the New Hampshire Republican Party and former Republican National committeeman from the state.

Still, in a nod to how limited the universe of non-MAGA voters will be, he said, “I don’t think you can be successful if there is more than one well-known moderate” running.

An adviser to one establishment Republican considering running for president in 2024 said that for a non-MAGA candidate, the “best case is that Trump doesn’t run.” If he doesn’t — and if an establishment candidate can raise money — “there’s a clear lane out there for somebody who’s going to be a, ‘Take us back to the basics of the Republican Party’ candidate.”

But it’s also possible that Dolan’s 23 percent showing overstates the ceiling for an establishment-lane candidate in 2024. Largely overlooked initially, Dolan avoided significant attacks from opponents, despite rejecting Trump’s lie that the 2020 election was stolen — sacrilege to much of the Republican base. A like-minded presidential candidate in 2024, if viewed as a threat, would likely come under a barrage of criticism.

Trump is already using Vance’s victory in Ohio to set the tone for the rest of the primary season. Fresh off Vance’s victory, Trump brought Vance to Pennsylvania on Friday for a rally for Mehmet Oz, the Senate candidate Trump is backing there.

At a minimum, Republican voters in 2024 will likely know which candidate Trump supports in the event he doesn’t run himself. In Ohio, internal polling in the Senate race suggested that about 83 percent of voters knew before the election that Trump had endorsed Vance. But that number was far higher among those who ultimately voted for him. In a presidential election with months of nonstop coverage, virtually every Republican will know Trump’s pick.

“Right now, if you’re looking at the anti-Trump capacity or elasticity inside the Republican electorate, it’s maybe 20 percent,” said Kevin Madden, who was a senior adviser to Romney in 2012.

For a moderate Republican, he said, “There’s a lane, and there is an opportunity in some states.” But among Republicans who vote most reliably in primaries, Ohio was evidence it is still vanishingly small.

“The thing about Trump,” Madden said, “is he just basically blocks out the sun.”