Establishment Republicans are growing increasingly confident of two things: (1) that Donald Trump won't be able to get to the 1,237 delegates he needs to formally claim the Republican presidential nomination, and (2) that Trump, after a weekend in which he refused to condemn the increasing violence at and around his campaign rallies, can't win a majority of delegates in an open or brokered convention situation.

As Philip Bump wrote this morning, without a win in Ohio on Tuesday, Trump can get to the 1,237 only through a relatively optimistic reading of the primaries to come. (To be clear: Trump is the only candidate who has any sort of reasonable path to winning the nomination before the convention.) As for the second point above, it's harder to say whether the establishment's confidence is warranted. Anecdotally, it seems clear that what happened in Chicago on Friday night -- and Trump's total unwillingness to take any responsibility for it -- has made some of his rivals who had pledged to support him as the nominee more wary to do so. My guess is there is some reflection of that in the rank and file of the party among those not already committed to Trump.

Let's grant all of that -- even though I could see Trump winning Ohio and picking up the necessary momentum to get to 1,237 delegates. So, we head to Cleveland in mid-July without a nominee. Trump is the delegate leader and Ted Cruz is in second place. Here are the realistic scenarios I can see coming to pass -- assuming, again, that Trump won't be able to win 1,237 on any ballot.

1. Cruz winds up becoming the nominee. It's hard for me to imagine that the convention delegates would pass over the two top vote-getters in the primary process in favor of a third candidate -- John Kasich? -- who may or may not even be actively campaigning by that point. So, Cruz then. A down-the-line conservative hated by much of the party establishment but, amazingly, the choice of many of those folks in this election in order to keep Trump from the nomination.

For all the attention Trump gets as a problematic general-election nominee against Hillary Clinton, the Texas senator is no great shakes, either. Trump has a lower floor (I think he could lose virtually every state in the right/wrong circumstances) but also a higher ceiling than Cruz. While Cruz will almost assuredly hold states such as Idaho, Wyoming, Kansas, Nebraska and so on, it's hard to see how he expands the map on which Mitt Romney got clobbered by President Obama in 2012.

Remember that the map above yielded Romney 206 electoral votes -- 64 short of what he needed to win. Now, pick a state -- or, even better, a series of states, where Cruz wins and where Romney didn't. Hard to see, right?

The Clinton campaign seems, likely because of the map above, to prefer running against Cruz to running against Trump. A race against Cruz is a very orthodox one for Clinton -- he's too conservative and will take the country backwards. A race against Trump, on the other hand, would be the definition of unorthodox.

Nominating Cruz then would be, at least based on the current numbers, a bad option.

2. Trump decides to run as a third-party candidate. Trump has made clear -- including in the latest debate last week in Florida -- that he thought the candidate who entered the convention with the most delegates should be chosen as the party's nominee by acclamation. He's also said over and over again that he won't break his pledge not to run a third-party candidacy unless he felt he was being treated unfairly by the party bigwigs.

What could be more unfair in the eyes of Trump and his unfailingly loyal supporters than the guy who won the most votes and the most delegates not being the Republican nominee? And what could be worse than the party choosing Cruz -- someone Trump genuinely dislikes and believes represents all of the bad stuff about politicians -- instead of him?

But he signed that loyalty pledge! you say. And he said in a debate recently he would support the GOP nominee! you say. To which I say: This is Donald Trump we are talking about, people. He is not someone who owes the national party anything or who feels terribly compelled to stick by past promises. If Trump thinks it is in his best interest to run as a third-party candidate, he will do it. Period. End of discussion.

If he did that, it would virtually foreclose Cruz's chances (or those of any other candidate who might win the GOP nod at a convention) of beating Clinton. Trump's supporters are as loyal as they come. They are also mostly regular Republican voters -- disaffected or otherwise. Those two facts mean that they would definitely (a) follow Trump out of the GOP and (b) in so doing, rob Cruz of plenty of reliable Republican votes. There's simply no way that a three-way race between Clinton, Cruz and Trump can be won by Cruz.

That would be an awful option for Republicans (obviously).

And so, under the best-case scenario for establishment Republicans, they have a bad or an awful chance of winning the White House. There is, of course, the long-ish shot theory that the convention chooses Cruz and Trump doesn't run as a third-party candidate. But nothing I've seen in this campaign suggests to me that The Donald would follow that path.