They aren't. They hate him. He is not their "Judas horse", Marco is. (Now that Jeb's out.) The GOP-E totally hate Cruz, esp. after he directed some National Republican Senatorial Campaign (NRSC) funds two-three years ago to Tea Party challengers of old GOP-E bulls, one of whom was Mitch McConnell himself. The Old Guard totally flamed Cruz.
They LOOOOAAAATTTHHHHHE Cruz.
In fact, just guessing (and Rush Limbaugh put this up, too), the current GOP-E leaders would rather try to do a "deal" with The Donald. He's made it tough for them, but dealing with Ted Cruz is a total DOA non-starter.
Heidi's CFR work is a totally different kettle of fish, and I've seen nothing tying her old man to an endorsement of any NAU nonsense, esp. after voters spanked Dubya on that subject 10 years ago.
NEIL BUSH, Jeb's brother, JUST JOINED CRUZ's MONEY TEAM!!!
GOPe ALL THE WAY.