It's not economic anxiety, it's people who've always been cruel finding a guy that makes fun of all the people they hate and worshipping him for it.
I feel like that 'economic anxiety' shit is given to them too much of an excuse. Sure, it may agitate things, but these are by and large people who were already innately hostile to anyone different.
It's sad, but that's what it is.
That's a big factor, but the Anglos and German immigrants played a big part historically, and it shifted eventually to eastern-European immigrant groups and Latinos as the moving target of "American" shifted from the late 19th century to the post-WW2 era to the current day. I'm far from an expert on it, but from what I know, a similar thing has kind of happened on the right in Brazil in Bolsonaro's base of ex-Catholics becoming born-again Evangelicals because of their relative comfort and economic security becoming at odds with Francis's more collectivist/soft-left messaging meshing with Lula's platform.