integrationist

noun

1. An advocate, supporter and/or practitioner of (social) integration, usually aiming for greater equality.

   “Instead the legal confrontation took place in the 1950s, when the Southern allegation “that integrationists were Communists” carried far greater resonance than it would have a decade earlier, and when “the power of the left to implement desegregation” — as Ms. Gilmore imagines it — no longer existed.”