From Grammarist:

The saying, Fool Me Once, Shame on You; Fool Me Twice, Shame on Me was first used in 1650 by politician Anthony Weldon. It’s a witty way to say that you should learn from someone’s tricks on you. If you don’t, you’re the only one to blame.

Weldon was an English 17th Century courtier and politician.

I looked it up. That's one of those quotes that could as easily be attributed to Mark Twain (who may also have said it, or something more clever along those lines.)

That Long Island con man has operated under the national radar until now. Chances are he doesn't have the personal fortune to play the same massive shell game that Trump has managed.