social justice warrior

Short definition from Wiktionary

Noun

1. 1
   A person who advocates for progressive views or attitudes, principally with regard to social justice.
2. 2
   An advocate for social justice views whose actions are deemed overzealous, performative, or insincere.
3. 3
   Used other than figuratively or idiomatically: see social justice, warrior; a social justice activist.
4. 4
   Alternative form of social justice warrior.