“Why are there so many white supremacists in the U.S.?” is a good and important question, but you’ll get much better answers by paying attention to history than from any “Golly gee, Nazis shop at Target, just like you!” puff piece.
It’s not pleasant to have strangers online calling me out for enjoying a bunch of advantages I didn’t earn, never asked for, would share if I could, but still adhere to me solely because of how I was born. I understand the temptation to tell them to just shut up and leave me alone because none of this is my fault. The better response though, is to use what advantages history and society have given me to try to make the world better for everyone who didn’t get them. We’re not in a zero-sum game here: when other people’s lives are better, that makes my life better, too.