Ohio Gov. John Kasich transformed from establishment spoiler to potential Donald Trump spoiler with his home-state win on Tuesday night.

By nailing down the Buckeye State’s 66 Republican delegates in its winner-take-all primary, Kasich made Trump’s path to wrapping up the nomination before the party’s national convention much more difficult. Trump remains the undisputed frontrunner. But by failing to edge out Kasich in Ohio, he now needs to win roughly 60% of the remaining delegates to secure the necessary 1,237 to clinch the GOP nod — a tough, though not impossible, task.

If Trump had won Ohio, he would have needed only 52% of the outstanding delegates.

It’s hardly clear how a newly winnowed field will divide up the electorate in the remaining primaries.

Florida Sen. Marco Rubio quit the race on Tuesday night after finishing a distant second to Trump in his home state, Tuesday’s other winner-take-all prize. Just two weeks ago, Republican establishment leaders bemoaned that Kasich had sapped Rubio’s support in a series of Super Tuesday contests, keeping him from winning Virginia and suppressing his delegate collection.

It remains to be seen whether Kasich can translate the momentum from his backyard into victories anywhere else. But he’s too far behind in the delegate count to be able to win the nod before the July convention in Cleveland. His only hope, then, is for a contested convention that devolves into sufficient chaos to allow a candidate trailing in delegates to emerge with the nomination. In other words, he remains a very long shot.

Kasich has made a point of waging a relentlessly positive campaign in an ugly election season. Addressing supporters near Cleveland after the returns came in Tuesday night, he promised to keep it up. “I want to remind you tonight I will not take the low road to the highest office in the land,” he said.

Yet earlier in the day, Kasich signaled he’ll begin to draw contrasts with Trump, which he’s steadfastly refused to do so far. The governor told reporters he’ll be “forced going forward to talk about some of the deep concerns I have about the way this campaign has been run by some others, by one other in particular.” Referencing a new ad slamming Trump’s history of controversial comments about women, Kasich continued, “I just saw a commercial, I guess, last night of these comments that were made about women. I have two daughters. They see this stuff. What do you think they think? We’ll have more to say about that.”