Actually, they are insanely jealous of him.
He is so far not encumbered with skeletons in the closet that leave him open to blackmail like much of Congress and his ambitions seem to run towards higher office as opposed to personal enrichment.
This allows him the freedom to speak the truth and he actually seems to enjoy getting in his enemies face to speak the truth.
This allows him to nullify Democrats and beat them at their own games.
Cruz is the new Joe McCarthy and the domestic communists are out to destroy him
They got lucky because they controlled the message and demonized McCarthy, but will have no such luck with Cruz
And the CPUSA is terrified, because payback is coming, and its going to be fast, brutal, and merciless