The Ohio GOP primary could be the Republican establishment's last chance to stop Donald Trump. (Peter Stevenson/The Washington Post)

John Kasich put it succinctly two weeks ago.

"If I don't win Ohio ... ballgame over," he said on NBC's "Meet the Press" on Feb. 28, predicting (correctly) that his candidacy would hinge on winning his home state.

But it's not just Kasich's presidential run that hinges on Ohio's primary vote on Tuesday; in a sense, it's the GOP's last chance to stop Donald Trump from running away with the Republican presidential nomination. That will be especially true if the current polls in Florida are even close to accurate — Real Clear Politics had Sen. Marco Rubio down by almost 20 percentage points in his home state over the weekend, and the senator hasn't exactly looked energized on the campaign trail.

Kasich needs the momentum that an Ohio win would give his campaign; he's 0-for-24 in GOP contests thus far, and winning a winner-take-all state such as Ohio would signal that his campaign has more life in it than he has shown to date.

But it's not just about momentum; it's about delegates.

As The Post's Ted Mellnik and Weiyi Cai wrote Saturday, Ohio's 66 delegates could significantly affect Trump's path to a majority of delegates (as could a whole host of other winner-take-all states, Florida included, but Ohio looks to be the closest right now). If Trump wins both Florida and Ohio on Tuesday, they wrote, he will need to win 54 percent of the remaining bound delegates to clinch the nomination. But if Kasich somehow pulls out an Ohio win (and Trump still wins Florida, as expected), Trump will need to win 60 percent of remaining bound delegates.

That doesn't mean an Ohio win would make Kasich the front-runner — not hardly. Kasich openly admits that his only realistic path to the nomination is through a contested convention. But that makes preventing Trump from winning delegates more important than Kasich winning them himself.

Perhaps recognizing that, Rubio all but told his supporters over the weekend to support Kasich in Ohio.

"If you are a Republican primary voter in Ohio and you want to defeat Donald Trump, your best chance in Ohio is John Kasich,” Rubio spokesman Alex Conant said in an interview with CNN.

That's a surprising admission from a serious presidential campaign: "Go vote for that other guy." But it's what things have come to in Ohio. The Buckeye State is the GOP establishment's last, best chance to arrest Trump's momentum and severely imperil his path to winning the nomination outright.

Otherwise, it could be ballgame over very soon.