"She knows nothing about me, a total con!"

Correct.

This tweet has caused a lot of amusement across the internet.

That #45 refers to himself as a total con is wonderfully funny.

I thought he was reaching out to the Hispanic community, but he can't even get that right.

It's something like, "She knows nothing about me. Her case was a total con."

In grammar, this is called a "dangling participle". It is bad English and often leads to ridiculous mis-statments.

He meant to say that Stormy Daniels is a total con.

To avoid ambiguity, Trump should have tweeted "She knows nothing about me. She's a total con!"

But I think that since Trump wanted to impress you, he wrote in a colloquial way of emphasis: "A total con!" Unfortunately, he misused the comma.

I don't think that there was any ambiguity. Everyone knows exactly what Trump meant.

Not so absolute, Max. Better to know some psychology. When a healthy man lies, he would not cheat himself but rather tell himself in his mind "You've lied." In this way he keeps healthy and carefully makes more lies to cover the original. A man who cheats himself would more likely become schizophrenic.

Trump lies everyday, but he's not schizophrenic. So he most likely doesn't cheat himself. He keeps telling himself "You've lied" or "You're a total con, Trump, I know you" to keep alert and skillfully dodging any responsibility. It is possible that he made a slip of tongue to reveal this secret.

Even given that scenario, an unconscious slip isn't intentional. His tweet was generated by his conscious mind to the outside world. That's why it's a slip. It would also call into question Trump's mental health in regard to his lies.