Cruz cannot have relationships both ways. He cannot pride himself on not getting along with his Senate colleagues, then turn around and smooze up to Carson.
Cruz is starting to "reap the whirlwind" of that approach. What goes around, comes around.
Note: If Trump compared Carson's youth violence to pedophilia, it was from the standpoint of it being a severe personality disorder; e.g.. if acute, not reversible. Carson said it was not so. And neither have spoken of it, since.