I don't think Trump damaged the office of the president or the institutions. He's actually a quality tester (or a malicious user), the flaws in the institutions were there before, he's the first to abuse them in this way.

Security and anti-terror laws, as well as propaganda for the Iraq war and other militant and jingoistic opinions were the beginning of this.

If the flaws aren't fixed, the US may get a competent dictator within our lifetimes.