Just responding to the headline:
Of course conservatives (Cruz supporters?) should support Trump.
But what about that other question: Should Trump supporters support Cruz if he wins the GOP nomination?
I would support any Republican over Hillary or Bernie and I would hope that all Cruz and Trump supporters would do likewise.
However, even accepting that it occurred, Cruz would lose in a landslide so massive that conservatives would be tarred with the failure brush for 50 years. Hell, they are still bringing up Goldwater, never mentioning Reagan. Whatever conservatives here ended up doing, I can guarantee that voters throughout this land would be so disgusted with the Republican party that a third party would likely form, and Hillary would be elected. Cruz would be lucky to get Romney's states.
Continuing to support Cruz is like hoping for a Hillary (or Biden) victory. Voting for Cruz in November would be a futile gesture of wishful thinking.
But what about that other question: Should Trump supporters support Cruz if he wins the GOP nomination?
I would support any Republican over Hillary or Bernie and I would hope that all Cruz and Trump supporters would do likewise.
If Cruz gets close to the number of delegates as Trump and he wins in an open convention then I will support Cruz.
If Cruz is two-three hundred delegates behind and wins an open convention I may support Cruz.
It neither Teump nor Cruz is the candidate I do not see myself supporting the Republican candidate. Further I will always have a certain animosity toward Cruz and his supporters if that happens when we had one chance to take down the GOPe.