You didn't see it to the same degree in the past because you weren't exposed to the same degree of coverage of it. Doesn't mean it wasn't as widespread. You don't see anything in a dark room until you switch the lights on.It didn't happen to anywhere near the same degree as we see now since the advent of social media.
You didn't see Bill Clinton win an election result in millions of insane cultists forming the Bush version of QAnon. People no longer accept being wrong at all, or even on the defeated side; it's a different animal.
You can have the same argument about football - Compare when there was one game a week on the TV and to now and it's total media saturation. Even this season it feels like there is more football than recent years but it's not more games being played, just more coverage.