So is that really it? Is Donald Trump now the presumptive presidential nominee of the Republican Party?
Seems so - and yet, don't oversell it. His train could slip the rails yet.
With the Tuesday Indiana vote in place, Trump seems to have collected 1,047 delegate votes. That puts him just 190 short of the 1,237 needed to win on the first ballot on the floor of the Republican convention.
With the departure of Texas Senator Ted Cruz from the race, Trump is well positioned to take to take nearly all of the 445 delegates still up for grabs in the nine states remaining. Even with Cruz still in the race, Trump was likely to win the bulk of the delegates to come (West Virginia, Oregon, Washington, New Jersey and California all were likely to go his way). Now, with only the barely-financed and slightly-organized John Kasich campaign standing in his way, he will probably emerge with all but a few dozen of those delegates. Maybe more than that.
And that would seem to be that, and it could be. If Republican organization honchos decide, as they may, that they'd be better off just letting the Trump train run through the rest of the nomination process and then hope for the best, he might in fact get the nomination without too much squabble.
But the recognition of the possible damage Trump could do to the Republican Party as its presidential nominee is not lost on the party leadership, or on the rank and file. And there remain tools available to send this whole thing off in a different direction.
The big one is credentials rules. It's been a few years since either of the parties had a good credentials fight, but it's happened before with far less provocation. The convention, through its rules, has the right to determine who can be seated there as an official delegate, and who can cast a vote. Looked at generally, there's nothing unusual or out of line about the way Trump collected his delegates, but if you want to scratch around for details suggestive of irregularities, you can come up with raw material here and there. (The most mentioned such case may be Trump's big cache of votes from South Carolina.) Knock out just enough delegates - and this would be done at the beginning of the convention, before the vote for president occurs - and you could knock out Trump.
Various other rules could be enforced rigidly, or new rules concocted. As you read this, Republican activists all over the country - probably including strategists on Trump's behalf, in defense - are considering all the many possibilities.
For now, it seems reasonably to say that Trump is the default nominee, the guy who will get the job unless something comes along to change that. And it will probably happen.
But nothing is 100% certain until after it happens. He's not the nominee until the convention votes have have been cast and counted. Until then, watch carefully.