That sounds like a Roman Catholic take on Christianity.
This is better than NO take on Christianity, of course. God can fix distorted belief better than NO belief.
While Cruz isn’t technically a NO belief situation, indulge me in a little “concern trollery” as to whether he buys into the dominionist wishes of his papa towards him (his papa’s son). If he does... that’s a heaping helping of self will sitting where faith in Christ really ought to be. Jesus refused the devil’s offer to give him the kingdoms of the earth prematurely (before God snatches them from him) over this issue... it’s not the most trivial thing in the world, let’s say that.
Please take this not as an absolute statement of bad news, but as a pointer to a wisp of smoke coming from his house. Maybe he just burned the beans, or maybe his house is on fire. We might want to look.
Hardly surprising, seeing that Santorum is a Latin (in the sense that the most scrupulous among us Orthodox use the word to not credit the claim of the adherents of the Papal Throne of Rome with their claim to catholicity).
I think Santorum is upset that Cruz would allow the states to have their traditional say on moral matters, rather than using the same concentration of power in the Federal government that now assaults traditional morals to enforce a one-size-fits-all version of traditional morals on the country as a whole. Maybe Santorum should review the notion of subsidiarity in his church's social teaching, and remember that the old notion that "error has no rights" has been replaced with the realization that those who hold errors do have rights. The use of Federal power to enforce a one-size-fits-all policy of any sort (leaving aside in foreign affairs) is the negation of subsidiarity.