When I was a kid, two subjects were off limits for polite conversation: politics and religion. All these years later, I don't see many people talking about religion in social settings, but man, the no-politics idea has been smashed all to hell.
There are so many things I hate about politics that it's hard to know where to start, but today I'm sticking to social media.
Stating your political beliefs on Facebook and Twitter is fine.
A good-spirited debate is less fine, in my never-humble opinion, but still okay.
Assuming that everyone who friends/follows you shares your beliefs is naive and harmful to a friendship.
Ranting that if your friends/followers don't believe exactly as you do, they are responsible for the destruction of the universe and should die a slow painful death crosses the line.
My opinions are very strong, and they're mine. I don't try to ram them down someone else's throats. I don't automatically assume that if you're a Democrat, you must believe this, or if you're a Republican, you must believe that. I don't insult people publically for daring to disagree with me, and I don't take kindly to people who try to deny me that same right.
(Except for people who vote straight-party tickets. It amazed me back when I was in grade school and found out there were people who actually voted for someone for no other reason than he was a Republican or a Democrat, and it absolutely astounds me today. Vote the issues. Vote the candidate's track record, for God's sake. All Democrats are not created equal, and neither are all Republicans.)
Campaign for your candidates. Give money to your party. Nurture your beliefs.
And please grant everyone else the right to do the same.