If you just do a little research, you can easily find a long list of all of the failures Trump has had. There are a LOT of things he is not good at. The one thing he IS good at is self-promotion. At that, he is a genius. But the job of president requires a lot more than that, and Trump doesn't appear to have what it takes.
If you don't fail once in a while, you're simply vegetating your way through life. In his environment, he probably fails more that most folks, but he also wins, and wins big! Now, I direct your attention to our “Congress!” They have a patent on failure! Will President Trump fail, sure! Will he win absolutely, unlike Cruz and the other “current and former government officials” who are running against him. Cruz hasn't been remotely successful as a Senator, neither has Paul or Rubio. And don't get me started on the 1%ers, who in many respects, are even worse that the three sitting Senators. I've actually had a mini-epihany of sorts in that I finally see the “conservatve movement” for what it really is, an abject failure. A bunch of idealogs who care more about their precious “principles” than in actually accomplishing anything of value for their country, Sure, I still believe as they do, but I can readily see that they are ineffective at leading because they are hidebound by their own dogmatic approach to government.