my parents are voting for him because he's racist. They're old, white, and racist too, so I guess it's some form of tribalism. They see themselves represented by the disgusting behavior of drumpf, and wish to uplift him almost as if it venerates/excuses their own racism/sexism/xenophobia. They think "We can't be the bad guys, look at how popular someone with the same ideas as us is!" them voting for drumpf is really them voting for the idea that they're actually good people, despite everything their children/peers/idols are telling them.