Trump comes from a WASP family that looked down on and exploited Irish Catholics, immigrants, and working class people. (Along with blacks; remember Fred Trump was a Klansman, and the KKK hated Catholics and immigrants as well.) Biden was alluding to this history, suggesting that Trump continues to carry on that rich WASP superiority complex no matter how much he pretended to care about the WWC, and I thought it was a powerful moment.
Also, leave the forum for a year.
The only thing I’ve heard of Fred Trump being a Klansman was that he was arrested at a KkK Rally. Is there proof he was marching with the Klan that day? Was there other evidence suggesting his Klansmanship?
Who would be at a Klan rally that wasn't a participant or an eager onlooker?
Counter-protesters?
Perhaps, but I don't think Fred Trump would ever be a counter-protestor. Maybe he didn't support the KKK whole-heartedly, but he sure as hell wouldn't take a leap and protest against them.