>> those with directly opposing views are a constant source of drama and tension in your life

I don't think this is true at all. The vast majority of people largely ignore politics, cast their vote, and move on with their lives. It's completely fine to have different political views if you both act like normal reasonable people. We see a lot of the 'kick, scream, and cry' types on both side in the media. In the real world, most people have more important things to be getting on with.

Political views can change over time though. It can be unsustainable in the way of "one or both people moderates their political views".

That will leave a large group of people without any partners, since men and women vote very differently.