There are very few things in my research that admit to a political slant. In other words, there is little that I can do to appeal to the left / right dichotomy, even though I skew heavily left in my own political views.
It just doesn't seem that that dichotomy is intellectually productive in any real sense. Where it does come into play, it is orthogonal. For example, if I were studying or teaching Miguel Hernández's prison poetry, my main point is not to prove that his imprisonment itself was unjust: that is a given, something all but the most rabid Fascist would deny. If I disagreed with another scholar, it would not have to do with that issue.
In a sense, a certain left-wing position is simply implicit, unquestioned and unquestionable, in my field. More politically conservative people or ostensibly apolitical folks often study medieval, or science and literature things.