What do you expect? Trump supporters tell them all the time that they’re irrelevant, he doesn’t need them, conservatism is old news, and every one of them they lose isn’t important, they’ve been replaced by two dem crossovers, doncha know? Hear it enough and some will say “okay, fine, good luck out Democratting the Democrats.”
I’ve always said I like Cruz. It was his supporters that convinced me in late 2015 I didn’t want to be a part of it. Nonetheless, if Cruz wins the nomination, I will vote for him eagerly and proudly.