Trump revealed highly classified information to Russ. foreign minister and ambassador

[Brian37]

He has billions of dollars in debt too, so he was probably out of his depth as a businessman as well.

How do you go bankrupt running a casino where people give you their money for fucking nothing?

Not that simple. No matter the business, it still has to do with accounting and marketing. You can spoof your way for a while but in the end people can eventually see through the con. Keeping it up long term depends on you spoofing long enough to drag your con out in courts, and that is what he did. 

And Trump like far too much of Wall Street, has written our laws to benefit them, so what once would be considered illegal racketeering has merely become legalized theft. He got away with stiffing his university investors by paying a fraction of what he conned them out of.