I think 'they' is way too broad. Some companies banned Trump from their platforms. Those companies aren't particularly involved with the policies.
> the thing they fear the most of all is armed and genuinely effective resistance
I strongly doubt it. Such things are so rare and unlikely, not only in the U.S. but in democracies in general, that it's not too far off saying 'what they fear most is a giant meteor strike'. Well that would be a big problem, but not what is most feared. There hasn't been one in the U.S. since the Civil War, and that one came top-down, from the power structure.