Well if, as a billionaire, he's still looking for more power and more money, what does that say about his mental state?
On the other hand... what if he was Cruz's V.P.? That might be pretty spectacular.
There is no way that Donald Trump - who’s ego is surpassed only by Obama’s - would accept being a VP. He will either be the Republican candidate, be a 3rd party candidate or bow out entirely.
As for his mental state, I’m an old enough New Yorker to remember his past. That’s exactly why I ask the question “Is this an honest-to-goodness change or are we being swindled”? I think he’s perfectly capable of both.