They were never on the hook.
The idea of prosecuting a former President or your current opponent is unthinkable, or at least it will be until the Democrats do it.
there has never been a president or ex-president run a coup on an elected president in the US. Why would we give an ex-president carte balance to commit any crime they want? Clinton and Obama and the others belong on prison or there is no equality or rule of law.
It looks like President Trump is trying to protect the office of the Presidency and it’s traditions. It just isn’t done.
However, when Trump leaves office, the dims will go after him anyway.