But in a practical sense, there will be a lot of pressure over the next three, slow months to fall in line. There are lots of reasons for people to be worried about or skeptical of Trump, but there’s also lots of incentive to avoid four months of vicious in-fighting that further pits the party’s leaders against what is apparently at least a third (if not more) of the party’s voting base. There’s incentive for prominent Republicans to Put the Party First, as the saying goes, both from the standpoint that it gets them in the nominee’s good graces and from the standpoint that it dampens the turmoil.

Each time Trump picks up another member of the establishment, he gains momentum moving forward. It weakens the argument that he’s unacceptable and provides an additional disincentive to keep fighting him. It makes it easier for others to do the same thing. It’s the snowball effect. And since Cruz has an even bigger delegate hole to fill, each new bit of support for Trump makes it more likely that the party will start looking at Cruz to give it up.

The best-case scenario for party leaders is that Trump loses the nomination in a delegate battle at the convention, a battle that would almost certainly cause some sort of upheaval — perhaps even a violent one, as Trump himself has suggested it would be.