What the Trump campaign did was more aggressive and dishonest. They took it too far, finally inspiring a backlash. It happens with lots of things: crime, financial bubbles, etc. Eventually you hit a critical mass and a reaction starts. Once started the reaction spreads virally and feeds on itself.

It also doesn't help that Trump is allied with and most ardently supported by neo-Nazis. Not claiming all his supporters are such, but that's obviously his most vocal and enthusiastic base.