In the early Clinton administration, variations of "he's not my president" were standard stuff on conservative talk radio and conservative discourse generally. If one wants to Both Sides it, random assholes on the internet would say the Bush presidency was illegitimate. But even if we grant those are precisely the same things, there were never any elite validators of the latter. Democrats fought each other to the microphone to declare Bush was president.
Sort of the point of my "My President" joke about Trump. Issues with the electoral college as established aside, we did actually elect that asshole, as far as we know.
