Surely you jest!
What do you think the criteria is for every subjective question/response tool used in education? Facts are facts, and those can be challenged if a prof tells you "black is white". Math is pretty much right or wrong, except where the methodology for gaining a solution is what is being judged. Everything else is subjective: writing style, method of expression, method of analysis, results of analysis, methods of research or survey (and results), even historical events can be viewed in different ways.
Do you have a specific example to share with us? Have you been graded on a political topic in a manner that you feel bends facts to favor the prof's own ideological/political beliefs?