Why would you think poor whites are to blame? If anything they are getting even more shafted than minorities: there is 0 sympathy if not outright hatred for poor whites, males in particular. Witness the opioid holocaust.

I would instead blame all the elites that profit from the unfortunate but very real and universal human tendency towards racial prejudice. It is the oldest trick in the book, you identify some sub-group, preferably through something obvious like race, and you blame another groups woes on them. Politicians play that game, the news media plays that game and social networks accidentally machine learn it. It is all obvious and disgusting and treasonous.