I have. Rubio would not be in the race, nor would Trump. So, either the GOPee voters would hold their noses and back Cruz, or let it burn. Either the Trump supporters would vote for Cruz or stay home and pout.
We haven't had a situation where we'd find out if those who didn't support a Conservative in the primary would vote for the Conservative in the General. If Cruz does not get the nomination, that test will not be made this time either.
You had a lit of "ifs" in your post - keep telling yourself that while stressing the word "conservative" - you have only your mind telling you how bad somebody who isn't Cruz will do, but you insist on thinking the worst so you have an excuse to allow the Dims another shot.