Trump could play this numerous ways, depending on what his motives are.
Way 'A', if he wants to vet Cruz for a potential VP, would be take do so privately directly with Ted, and make a plan that does not burn any bridges, for Ted, nor for Ted's supporters.
Or, Way 'B', by burning bridges. As he is doing, but going very public, daily, with constant jibes.
It's more like, to me, Trump is trying to blow himself up.
No. Trump is not trying to blow himself up.
Trump is obviously and clearly trying to win, which is what he has plainly stated is his goal.
Trump is not a dishonest guy. He tells you exactly what he’s going to do, and then he does it.
But still there are people who think oh no he’s secretly doing this or this or he’s working for this person or that person and on and on.
He’s trying to secure the nomination, simple as that.