PARTISAN (POLITICAL)

In politics, a 'partisan' is a committed member of a party.
In multi-party systems, the term is typically understood to describe a person who supports their party's measures without an eye to fairness or compromise with their opponents.
In Commonwealth Realms, for example, the monarch is seen as being distinctly non-partisan and thus is vested with certain powers to form or dissolve governments when there is a democratic impasse. This is in contrast to professional politicians who are expected to push for their party's interests.