My (subjetive) take on this is that while racism always have existed here, far right have made it acceptable to be openly racist. Or even be proud of being racist, sexist, homophobe, transphobe, etc. Like a racist version of a spoiled teen throwing a tantrum and repeating the actions that get him scolded to show the adults they can do what they want. They feel like "rebels" against "political correctness".

I think it startes more or less at the same time. But got worse/acelerated with Trump. Propaganda usually help this kind of people. And when they are rightfully called on their shitty actions, they play victims.

On the other hand, having them on the open might make other people react and stop ignoring the problem. We need to stop giving them a pass by considering them "normal".