Ted Cruz is more interested in winning the Republican nomination than stopping Donald Trump from winning it. And that's very bad news for the stop-Trump strategy in Florida.

Donald Trump is poised to win the Florida primary on March 15, giving him all 99 of the state's delegates in its winner-take-all primary.

"If we win Florida, it's over," Trump said at a rally this weekend — and while this is coming from a man who reportedly doesn't know how delegates work, he's probably right.

But there's one candidate who might be able to stop Trump and save the strategy: Marco Rubio.

Rubio is still behind Trump in the polls in his home state. But he's been closing the gap. A Monmouth poll released Monday found Rubio only 8 percentage points behind Trump. And thanks to early voting, which started in Florida on Saturday, Rubio probably has a serious head start on John Kasich and Ted Cruz.

Former Republican nominee Mitt Romney explicitly said in his speech against Trump last week that voters in Florida who wanted to stop Trump should vote for Rubio.

But Ted Cruz doesn't want to stop Trump; he wants to win. And to keep his chances alive, Cruz is willing to kneecap Rubio in Florida and hand the state to Trump.

Here's what's going on.

Cruz is making a play in Florida to push Rubio out of the race

In the days after (the first) Super Tuesday, the Cruz campaign and its supporters made several aggressive moves in Florida.

On March 4, the Cruz campaign announced it was opening ten field offices around the state. The campaign is considering having Cruz himself visit the state later this week, around Thursday's debate in Miami.

And a Cruz-supporting Super PAC, Keep The Promise I, has cut a series of new ads attacking Marco Rubio that it plans to air "including if not especially" in Florida.

One of the super PAC's ads attacks Rubio for his role in the 2013 "Gang of Eight" immigration bill (something it's hard to imagine Rubio voters don't know about). The other two are pretty far in the weeds: one hits Rubio's poor voting record in the Senate, and the other attacks his support for sugar subsidies.

It's not clear how many Rubio supporters these will win over. And since Florida airtime is monstrously expensive, and Keep the Promise I hasn't said anything about how much money they plan to spend, it's entirely possible that the ads are intended simply to intimidate Rubio.

That would be in line with the Cruz campaign's goal: not necessarily to beat Rubio in Florida, but to convince him to drop out and narrow the field for the rest of the primaries.

The payoff for Cruz is clear. Rubio is struggling tremendously in the primary so far. Even if he wins Florida, it's really hard to envision him getting to 1,237 delegates. If he doesn't win Florida, it could be so embarrassing for him that he could drop out of the race.

The Republican establishment wants to stop Trump. Ted Cruz wants to beat Trump.

The problem is that if Rubio doesn't win Florida's 99 delegates, someone else will. And that someone is likely to be Donald Trump. Then, he'll be on pace to win an outright majority of delegates by the end of the primary.

That's the "stop Trump" crowd's worst nightmare. As long as Trump doesn't have a majority of delegates, they can force a brokered convention in July, and presumably emerge with a non-Trump nominee.

So it's not surprising that many of the stop-Trumpers have turned their energies to preventing Trump from doing well in Ohio and Florida, and urging all three non-Trump candidates — Rubio, Cruz, and John Kasich — to stay in the race for as long as possible to keep Trump from consolidating support.

The strategy seems a little odd, but it makes some sense.

Think of it this way. To date, Cruz has performed far better than any other non-Trump candidate — and it's not close. But arguably, Cruz has benefited from a favorable schedule in the early primaries — lots of states with heavy evangelical populations that organize in favor of Cruz.

He's less strong in more secular states in the Northeast. Donald Trump, on the other hand, is very strong there. So as the calendar turns to states with fewer evangelical voters, the best candidates to defeat Trump there might be Kasich or Rubio.

This is not, however, the way Ted Cruz's campaign sees it. After all, their goal is not to stop Donald Trump from getting the nomination. It is to win the nomination for Ted Cruz.

The Cruz campaign says that if elites are serious about stopping trump, he can consolidate the anti-Trump vote behind him if only given the chance. If he's wrong and Trump gets the nomination, that's a very bad outcome for the stop-Trumpers.

But for Ted Cruz, it's not necessarily any worse for the nomination to go to Trump than to Rubio, Kasich, or anyone else.

Why isn't Rubio being pressured to drop out and endorse Cruz?

The Republican establishment doesn't have much leverage to get Cruz out of the race. Unlike Rubio, he still has a Senate seat after the November election and a constituency within the conservative evangelical community — and he'll have those whether or not the party approves of him.

But more importantly, the establishment hates him, and he hates them right back.

This inability to back Cruz is, arguably, why the party is in this mess to begin with — if the Republican establishment unambiguously feared Trump more than they hated Cruz, they would have lined up behind Cruz after Iowa.

Why is so much of the Republican establishment continuing to back Marco Rubio's doomed candidacy — even as many of them acknowledge the campaign has been a wreck? Why not urge Rubio to drop out, endorse Ted Cruz, and save the party?

It wouldn't take too much. Rubio doesn't have any career prospects after his presidential bid ends: he has made it all too clear that he's not interested in returning to the Senate, and he's going to have a hard time running for governor in 2018 if he can't win his state's presidential primary in 2016. But the party apparatus, donor class, and lobbyist corps — Rubio's natural base — have plenty of jobs and money to offer.

Heck, if Rubio drops out before the Florida primary he might even save enough face to reanimate his political career down the road.

It's possible that such offers have been made, and that Rubio is simply too stubborn to accept them. But it's more likely they haven't been offered because the Republican establishment appears to be totally, completely, 100 percent unwilling to line up behind Ted Cruz.

The stop-Trumpers say that any of the non-Trump candidates in the race would be preferable to Trump. But many in the Republican party apparatus don't actually see it that way; they think that Cruz and Trump are simply different flavors of terrible. And many of them are genuinely willing to risk a Trump nomination rather than give the party to Ted Cruz.

Back in January — the last time it looked like a two-man Trump/Cruz race — the New York Times' Jonathan Martin wrote an article examining this. It's held up extremely well, and I highly recommend you read it. Here's one representative quote:

"We can live with Trump," said Richard F. Hohlt, a veteran lobbyist, reflecting his colleagues’ sentiment at a Republican National Committee meeting last week in Charleston, S.C. "Do they all love Trump? No. But there’s a feeling that he is not going to layer over the party or install his own person. Whereas Cruz will have his own people there."

There are lots of justifications like this. But what many of them come down to is that people like Hohlt really, really, really hate Ted Cruz. As Bill Kristol told Martin, "Cruz is so hated in Washington that there’s this distortion about him."

Kristol is a stop-Trumper: if it came down to it, he'd support Cruz over Trump. And it looks like it really will come down to it — if there's going to be any hope of stopping Trump at all.

The question Republican establishmentarian Rubio supporters will have to wrestle with over the next few days is this: do they really hate Ted Cruz that much?