I might remind you that this is a contested primary election.
At some point, Trump and Cruz will need to contest each other.
I might also say that (based on numerous assertions here) Ted Cruz is not running for VP.
May the best man win...
I disagree. Cruz should continue to run on his platform, going after Trump won't put him on top, it will disappoint many who thought he was above those tactics. He's not Trump, he doesn't have the reputation of bashing people and it's not accepted.
Fair or not these guys have built their images and they are what they are.