Here's How the Republicans Are Working to Stop Donald Trump on Tuesday

Donald Trump's path to winning the Republican nomination is appearing more and more inevitable by the day, which has provoked various degrees of panic from the Republican party as they scramble to come up with a way to stop his seemingly Teflon-coated campaign. Tuesday's primaries are likely the last opportunity Republicans have to stop Trump (no, really this time) before he locks down the nomination for good.

In order to halt Trump, the three other Republican candidates — Senators Marco Rubio and Ted Cruz and Governor John Kasich — need to deny the frontrunner from winning as many delegates as possible on Tuesday, even if that means ceding some victories to one another. The strategy goes like this: Rubio and Kasich need to win their home states of Florida and Ohio, respectively, leaving Cruz free to scoop up as many delegates as possible in the other three states holding their primaries Tuesday (Illinois, Missouri and North Carolina).

The strategy hinges on Ohio and Florida, which are Tuesday's two most decisive contests. They are the first winner-take-all primaries — meaning that the candidate to win the most votes gets all of the delegates in the state — with a combined 165 delegates up for grabs (99 in Florida and 66 in Ohio). The other three states voting on Tuesday award their 202 delegates on a proportional basis. If someone other than Trump wins Ohio or Florida, the GOP still has a shot at delaying the fight for the nomination until the convention.

Related: Marco Rubio Beats John Kasich in DC Primary — Barely

There are several indications that the non-Trump candidates have set this strategy into motion in recent days. The biggest sign came on Friday, when Rubio's campaign told voters in Ohio to cast their ballots for Kasich.

"If you are a Republican primary voter in Ohio and you want to defeat Donald Trump, your best chance in Ohio is John Kasich," Alex Conant, Rubio's communications director, said on CNN.

Florida is truly a make-or-break contest for Rubio, who hasn't even bothered to campaign in any other state for the last week. But Rubio is still trailing Trump by 24 points there, according to the most recent Quinnipiac poll released on Monday.

"We are focused on Florida, so don't be surprised if we don't do well in some other states next Tuesday because we're not there. We're here," Rubio said during an MSNBC town hall last Wednesday in Miami.

If he loses there, which is looking likely, it's essentially impossible for his campaign to continue on. Rubio may not call it quits after a loss in Florida, but it will be impossible for him to win the nomination on delegates at that point and a disappointing finish could cause his donors to flee to other campaigns.

Kasich is also laser-focused on winning his home state. He cancelled any events outside of Ohio and spent his entire weekend campaigning there. The governor said he is not even trying to win Florida, although he hasn't gone as far as to publicly push his supporters there to vote for Rubio instead.

"When people are for you, it's pretty hard to tell them to not vote for you," Kasich said Friday on CNN. "But I'm not spending time in Florida. I'm here in Ohio."

Unlike Rubio, Kasich has a real shot at winning his home state. The same Quinnipiac poll shows him tied with Trump in Ohio at 38 percent. Kasich's home-turf advantage is bolstered by support from Ohio's Republican party, as the National Journal points out, which has thrown its full weight behind their governor with an endorsement earlier this year. Local GOP leaders have also been campaigning for him across the state ever since, which is a notable contrast to the state Republican parties in Rubio's and Cruz's home states of Florida and Texas that have opted to remain neutral in the race.

Related: Trump Blames 'Thugs' and 'Communist' Bernie Sanders Supporters for Chicago Violence

If Trump wins Florida and loses Ohio to Kasich, his path to securing the nomination gets bumpier. Trump would have to win 59 percent of the remaining delegates in order to completely secure the nomination before the convention in July.

It makes sense that Rubio and Kasich are focusing exclusively on winning their home states, as they don't really have a chance to win anywhere else on Tuesday. But Cruz trails both candidates in the winner-take-all states and, in order to take as many delegates as possible away from Trump, he must focus on competing against Trump in the other proportional states. It appears as though Cruz is on board.

Cruz's main super PAC, Keep The Promise, cancelled a massive ad buy in Florida attacking Rubio last week and his campaign has said they haven't yet pulled the trigger on their own advertising in the state or in Ohio. A spokesperson for Keep the Promise, said Thursday that they would be focusing a $4 million advertising campaign on voters in Missouri, North Carolina and Illinois instead.

After spending much of last week in Florida, Cruz is largely steering clear of the state in the days leading up to Tuesday's primary and instead has spent all of Saturday in Missouri and Monday in Illinois. His wife, Heidi Cruz, is also holding events in North Carolina all day on Monday, after spending much of last week campaigning in Illinois.

"We are really focusing our efforts on the central and south part of Illinois," Heidi Cruz said during a campaign stop in the state on Wednesday. "We've brought some of our very best people from our headquarters to Illinois, and on Tuesday, this is a key state for us."

Even if all of the forces align on Tuesday to slow Trump's path to winning the nomination, his campaign won't be stopped immediately. Trump has about one hundred delegates more than Cruz, his closest rival. In the unlikely event that both Rubio and Kasich win Florida and Ohio, respectively, they would not come close to the magic number of 1,237 delegates required to win the Republican nomination. But if Trump's rivals could successfully take deny him as many delegates as possible on Tuesday, it could force a brokered convention in July and delay the choosing of the nominee until then.

Related: What Is a 'Brokered Convention' Anyway and Can It Stop Trump?

Rubio and Kasich have already been planning their campaigns around such a scenario, since it is the only one that gives them the slightest chance of staying in the race. Now, Cruz seems to be warming to the idea too, assuming it comes down to a two-man race in which neither he nor Trump has reached 1,237 delegates. "Reagan and Ford battled it out in a contested convention," Cruz told Fox News last Tuesday. "That's what conventions are for."

This last-ditch strategy to ensure a contested Republican convention was first publicly floated by Mitt Romney earlier this month, when he encouraged Ohio voters to cast ballots for Kasich and those in Florida to vote for Rubio. Romney, who is intent on making sure Trump is not the nominee, spent Monday campaigning with Kasich in Ohio.

A contested convention carries significant risk for the party because it could cost them the general election if it doesn't work. If Trump ends up becoming the Republican nominee, it means that the party had spent all spring tearing itself apart and attacking the candidate that they will then have to support in the general election against the Democrats. The fact that the GOP candidates and some members of their party are now seemingly open to a contested convention is an indication of just how much of a threat Trump poses.

Follow Olivia Becker on Twitter: @obecker928

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