All art criticism is political because all art has political implications  Clearly, the critic who chooses to address overtly an artwork' s political implications is engaged in political discourse
But those critics who attempt a purely aesthetic evaluation of a work, and ttherefore ignore the work' s political implications, necessarily, though perhaps inadvertently, end up endorsing the politics of the artist
Art that makes an overt social or political statement is the sort of art with which critics are typically concerned.