You have likely heard of “The Golden Rule”, which is usually described as: treat other people the way that you want to be treated. The New Testament version comes from Matthew 7:12 ( emphasis mine ):
12 Therefore all things whatsoever ye would that men should do to you, do ye even so to them: for this is the law and the prophets.
While talking with others about the current political situation I thought of a version of this that could be applied specifically to politics:
Govern in the way that you would want an opposing party to govern.
That is to say that while your policies and agenda may be different, the way you go about it should be completely above board and beyond reproach.