If Trump shouldn't be president because of his sexual harassment or worse of women, then (on the face of it) it seems arguable neither should some presidents have been president because they did the same or similar (e.g. JFK who may have coerced an intern named Mimi Alford to give oral sex to a friend of his while JFK watched).
If fair is fair, then the same people who have (rightly) criticized Trump should likewise criticize former presidents like JFK and Bill Clinton who sexually harassed women or worse. These same people should say something like: Trump shouldn't be president because he is a sexual predator, and neither should JFK or Bill have been president because they too were or are sexual predators.
However, I won't hold my breath because many of these same people who are criticizing Trump have a double standard when it comes to their own side. They will only criticize people who don't share their political views rather than being fair-minded and consistent and criticizing anyone (regardless of political affiliation or politics in general) who has sexually harassed women or worse.
In fact, if they were truly fair, then they would also criticize women who have sexually harassed men or worse. For example, if a woman touches or grabs a man's leg or butt, and he doesn't want it, then it's possible she has sexually harassed him.