“Social justice warrior” is a relatively new term (to me, at least) used in the last year by mostly-conservative culture warriors to describe a mostly-liberal person who–grossly simplified–pushes for diversity in the arts.
(A “culture warrior” in my mind is a term to describe a mostly-conservative person… I think it gained popularity with the publication of Bill O’Reilly’s book.)
I find it pretty ironic though because it seems to me that a person who fights for conservative cultural values is also a social justice warrior. “Social justice” as a basic concept is about equality and leveling the playing field. With regard to the recent Hugo nomination controversy, the conservatives (“Sad Puppies”) feel that they were disenfranchised from Worldcon (among other things). With regard to the less recent Gamergate culture battle, the conservatives (who don’t have a name other than “Gamergate supporters” so far as I know) feel that they are being pushed out of the games that they love (among many, many, many other things).
By a strict definition, I would say that anyone who feels culturally disenfranchised or threatened enough to fight back is implicitly a “social justice warrior,” and perhaps more generically, a “culture warrior.”
Obviously I know that conservatives would flip right the hell out to be compared in any way to an SJW (social justice warrior), which now to them is just a series of letters or mouth-sounds that means “a liberal extremist who needs to be stopped.” I just find words and their meaning to be really funny and ironic sometimes. The fact that a series of words with very specific meanings can be combined to make a phrase with a totally different meaning is interesting to me.
I guess in terms of common usage and political connotation we can think of a “culture warrior” as a conservative and a “social justice warrior” as a liberal.
P.S. Liberals seem to think that “social justice warrior” is a derogatory term (since it was coined or at least adopted by conservatives), but I have no idea what conservatives might think of “culture warrior”–I would guess they’d be okay with it since Bill O’Reilly popularized it.