In all fairness, a lot of white people got radicalized into in the alt right between 2008 and 2016. That Youtube algorithm.
Not to say they didn't have racist beliefs beforehand that predisposed them, but there is a segment of people that got a lot worse after Obama was elected.
This=.
Like
@Luke Cage said they were always racist they just didn't know how to express it or act out on it without being called out on it.
Now...let me show you something.
The Stop the Steal rally at the White House on Jan. 6 was organized, in part, by Women for America First, a pro-Donald Trump group started by Amy Kremer. Her daughter, Kylie Jane Kremer, was the main organizer and signed off on the documents for the event. In a piece by the New York Times...
www.rawstory.com
The stop the seal organizer (a white woman mind you) tried to stop the certification process for Barack Obama in 2009. She was a part of the tea party (the party of white resentment).
The tea party birthed Trumpism.
So yes, while racism has always been a running undercurrent in American life and white culture, it takes certain elements to bring it out.
All the podcasts, talking heads, trolls, memes, and propaganda that came out during those years just led them in the right direction.