This question already has an answer here:

Politics: When a person discriminates on sex they are sexist, race we call it racism, what is called when someone discriminates based on a political party?

marked as duplicate by sumelic, FumbleFingers single-word-requests Feb 21 '16 at 22:03

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • The word dogmatism was not proposed in the potential duplicate. It means unfounded positiveness in matters of opinion; arrogant assertion of opinions as truths. – Graffito Feb 21 '16 at 22:17
  • discernment. [facetious] – stevesliva Feb 23 '16 at 6:36

Such discrimination is called "partisanship."

Not the answer you're looking for? Browse other questions tagged or ask your own question.