Racists see the world as zero sum.

Privately, they believe that the Other (Mexicans, trans people, Muslims) holds the same views that they do. Some people do not mature/develop a theory of mind beyond a vague sense of tribalism.

Because given power, they would eliminate people unlike them, they assume that the Other would do the same.

Look into racist spirituality, ie White Identity - a common belief is something like racial “oversouls” which are naturally opposed to each other. Anything that benefits Black or Mexican folks are overt moves by those oversouls - affirmative action as a covert move to drive white men out.

The majority of these people don’t get into it/think about it enough to engage with the “oversouls” but I think it does align with their behavior. The internet has also unfortunately gotten things like Blavatsky and Evola into to the mainstream - dollars to donuts that the DOGE boys were introduced to those names on /pol/