Of course the GOPe and the rinos despise Cruz, he is no rino/libertarian like Rand Paul.
Cruz is the most hated man by the Paul/Romney/Rove wing of the GOP.
Rand Paul is not a RINO. But neither is Cruz, either. Rubio, Rove, Romney are all RINOs.
Rand Paul is a libertarian-leaning conservative.
Rand Paul is not in league with Romney or Rove, either, as they are GOP-e, and he is not.
It comes down to this: if Cruz (for some reason) ends up not being able to win the nomination, then as a conservative, you must support Rand Paul over ANY RINO, because libertarians (though not-so-good in many areas) are always better than a RINO. Always.