America is a very individualist country to my eyes. People see taxes as paying for someone else's healthcare or homeless shelter rather than paying for the things that everyone needs. There are only 2 sides in the election. Most people can't ever see themselves switching sides, it's a big change in thinking for a lot of topics. Hell the vote is usually decided by the turnout rather than people being convinced to switch sides. Trumps followers want him to hurt who they perceive as "their enemy", i.e. Democrats (and non whites ssshhhh). And in fairness he does and they are happy that he does. They don't envisage themselves ever in the group that he is attacking so whatever he's gonna do to them is fine. They do sometimes end up in that group though:

https://www.vox.com/policy-and-politics/2019/1/8/18173678/trump-shutdown-voter-florida