All identity politics presume hierarchy.
Without a hierarchal power structure, there is no ability to enforce the definition of “in-group” vs. “out-group” and the concomitant preferential treatment of the in-group.
It simply won’t do, for example, for white nationalists to have the Italians, or heaven forbid the Jews, to presume that they qualify as “white”! This same hierarchy that enforces the group definition, however, necessarily produces peer-polity competition between it and other such hierarchies (because the “out-groups” will form their own “in-groups” in response–creating competing hierarchies), and these groups must then grow and intensify to avoid being out-competed….