I disagree.
Trump knows perfectly well that:
(1) he isn't going to be able to do it (Presidents don't set prison terms for federal crimes - Congress does), and
(2) if he (or Congress) tried, the courts would slap him down, toot sweet.
He's just throwing red meat to the part of his base that doesn't know any better.
They are the "chumps" here, not him.
That's pretty much his entire base.
"I love the poorly educated." - Donnie
Any way, SCOTUS already ruled it's a First Amendment freedom of speech right. Let's not go throwing the baby out with the bath water. Seems like every time a Republican wins the White House, the Constitution ends up taking more of a beating than when a Democrat wins. Strange how that works....