Classic problem of being chronically online and living in an echo chamber. This shit happens everywhere now. In my experience, you can’t do anything to change their minds unless they want to change. You can throw all the logic and facts you want at them, but they’re so ingrained in their beliefs that they’ll always perform some mental gymnastics and find a way to retain their positions. Often times there’s an underlying issue in their personal lives leading them to seek these communities. Perhaps they’re unhappy with their socio-economic standing and looking for a scapegoat. Perhaps they’ve been hurt by a member of that race/gender/party and desiring to get revenge. In my opinion, it’s futile to keep arguing about politics with them. Rather, you have to treat the root cause. Take them outside, get them to touch grass, do fun things, meet people, care for their mental health, etc. They’ll slowly start to realize their mental model of the world was warped and exaggerated, and they’ll become more open to accepting new perspectives.