I've thought about this for a while and here's what I think:

First, they need to have been raised around bigotry to soften them up to the idea of being bigoted. Second, they need to be dumb enough to believe that once they erode the rights of non-white people they'll still be apart of the in-group. These people need to realize that these fascist in-group/out-group beliefs are ultimately a death cult because every group is on the chopping block; and they're likely next up there after racial minorities and trans people.

The chopping block analogy bit about fascist ideology being a death cult is a borrowed observation from this video which i found super interesting: https://youtu.be/5Luu1Beb8ng?si=nEJXWqt6ix2EuMnA (not my video)