The whole dynamic HAS changed.
If Cruz is as smart as I think he is, he knows he doesn't have the populist appeal to go to war with the party. Trump does.
He didn't have to raise his hand because he knew Trump is the guy, and he can get behind him.
I completely agree that Cruz, so far, probably thinks he doesn't have the "populist" (God I hate that word almost as much as "impacted") appeal to win a the nomination, but he is setting himself up for a key and active role in the Trump administration. I'm sure they've already discussed this at length.