Ted Cruz and Donald Trump are our last great hopes. If the GOPe is successful in kneecapping Ted out of the nomination, then Trump can go forward as a.third party candidate and wage war against the GOPe candidate.
In any event, the most important objective of the 2016 campaign should be the utter political destruction of the GOPe-led Republican party.
First there is no "last great hopes" because you have no idea what the future holds.
Second, if you really think Trump is that vital to conservatism I feel kinda bad for you considering Trump's long liberal track record (on positions and pouring money into the coffers of liberal politicians).
Cruz is terrific, but Trump is effectively boxing him out right now. Cruz is a "tell it like it is" guy, and Trump is siphoning off that support from people who don't know that "the Donald" is a clown out only for himself and his brand.