It is hard to recall now but before the 2016 election, blatant contempt for the rule of law and other longstanding (small-r) republican values, public displays of stupidity, extreme character flaws, and irrefutable evidence of psychological instability could wreck a presidential campaign; and it was practically axiomatic that no presidency could be headed by anyone to whom those descriptions apply.
No longer. By force of example, Donald Trump has proven the conventional wisdom wrong.