Partisanship
Part of speech: noun
Definition: An inclination to be partisan or biased; partiality
Example sentence: When Kansas and Missouri work together, we can accomplish a lot - and also set an example at a time of extreme partisanship.
Partiality
Part of speech: noun
Definition: Preference, bias in favor of, tendency.
Example sentence: I have developed a very strong partiality for the dead: they don't talk back, they don't sue, and they don't have angry relatives.