yeah people act like it's 100% the cult but there are soft trump supporters who actually don't like that he's a criminal scumbag and because our system is stupid it doesn't take all that many of those to stay home to swing it
I've personally persuaded multiple people who have voted for Trump not to after 2016. It absolutely can be done and is worth the effort, particularly if those people are close to you.
I mentioned some examples elsewhere but the big thing is finding ways to relate to them. To be clear, if you don't have any relationship going in this will be much harder to impossible. But if you do, focus on that relational end. You'll know better than me what might make sense in that case.