I think it will cost him all his remaining credibility, because his entire appeal is that the idea that he's so authentic that he doesn't care if he repels people.
He's so personally loathsome that even his political allies despise him, and his public appearances make people's skin crawl. But that was countered by the "tough medicine" shtick that conservatives swoon for: it's supposed to be a mark of pride that he's obnoxious, because he's not trying to pretend -- he's honest. You need him on that wall. All the silly stuff that adolescent boys think of as virtues, and which life experience teaches are just as cynical and manipulative as any other pose.
Cruz now has Hillary's problem -- he's implicated in the establishment's rape of the white middle class because he's just another Wall Street flunky. That destroys his whole appeal.
I think the GOP just became Trump v Rubio. Hopefully they'll pull a Montreal Screw Job on Trump and he'll be so miffed that he runs third party. And won't it be fun to watch down ticket candidates have to squirm on which one they're endorsing.
