WEST PALM BEACH, Florida – Facing a nearly insurmountable delegate deficit and the threat of Donald Trump possibly running away with the Republican presidential nomination if the billionaire wins the Florida and Ohio primaries next week, Sen. Marco Rubio’s campaign acknowledged Friday that Ohio voters who oppose Trump should vote for Gov. John Kasich.
At a news conference with Jewish leaders, Rubio stopped short of asking his Ohio supporters to vote for the governor.
"I’ll leave it to John to make that argument,” he said.
But a senior adviser told NBC News that Rubio’s campaign is essentially "releasing" his Ohio voters to Kasich. The adviser said if Rubio wins Florida and Kasich wins Ohio, "it'll be a whole new day."
Such a scenario would prevent Trump from taking two of the biggest delegate pots next Tuesday, when a number of states voting award all of their delegates to the primary winner, and help slow his march to the nomination. It would also help ensure the primary fight heads to a brokered convention, which both Kasich and Rubio's campaigns have acknowledged are their only remaining path to the nomination.
Most polls of Ohio have shown Kasich with a slight lead over GOP front-runner Trump, while Rubio lags Trump in polls of Florida by anywhere from 6 to 23 percentage points.
While a win for both Kasich and Rubio in their respective home states would shake up the race, if Rubio loses Florida, "It'll be a dark day," his adviser said.
Rubio himself wouldn’t speculate about what would happen Tuesday if he fails to overtake Trump.
“I haven't thought about anything beyond Tuesday night,” Rubio told NBC News in an interview inside his campaign bus. “But we're going to win Tuesday night, so I won't have that decision to make.”
Rubio insists there's been no formal discussion with the Kasich campaign -- and he dismissed any notion of a so-called unity ticket with either Kasich or his other rival, Sen. Ted Cruz.
“This is stuff from, like, 'House of Cards,’ he said. “That's not real life.”
WATCH: Rubio flailing in new Florida poll
It’s also possible the Rubio campaign could be trying manage expectations for what’s expected to be a disappointing finish in Ohio, Kasich’s home state where polls suggests he’s locked in a tight battle with Trump.
Rubio has been fending off threats from Cruz and Kasich in his home state.
"We agree with the Rubio campaign that the best chance to beat Donald Trump in Ohio is by voting for John Kasich, and in that spirit, Sen. Rubio should immediately tell his Super PAC to stop attacking the governor," said Chris Schrimpf, a Kasich spokesman.
Conservative Solutions PAC, the Super PAC supporting Marco Rubio, is airing advertising in Florida and Illinois attacking Kasich, but those ads are not airing in Ohio.
But the Kasich team is already fundraising based on the Rubio campaign’s suggestion today that voters who oppose Trump vote for him in Ohio.
Last week in Detroit, Kasich was asked about this possibility and whether he would encourage his own supporters in Florida to vote for Rubio to get everyone closer to a contested convention.
“What kind of a question is that? A good question. A tricky question,” Kasich mused. “I think it is important we stop Mr. Trump. He is not my pick for president and you know I want to have a more positive approach to the solutions of the country, so let’s see where things go down the road here. Let me just put it to you this way: I am going to spend a lot of time in Ohio, and I bet Mr. Rubio is going to spend a lot of time in Florida."