In an email interview that transpired over the course of a couple of weeks, Dallas Mavericks owner and Shark Tank Reality TV star Mark Cuban details why he had a change of heart, rescinded his support for Trump, and eventually endorsed Hillary Clinton. It's clear that he is being rather tactful and not divulging all of the reasons why he's no longer here for Trump. But he does touch on some overall concerns relating to foreign policy, nuclear weapons, and Trump's glaring incompetence.
"I liked Trump’s honesty because it was different and had a chance to change the business of politics. What I didn’t realize he was missing at the time was a complete and utter lack of preparation, knowledge, and common sense."
"Why Mark Cuban Changed His Mind on Donald Trump"