Certainly the freedom of people to choose who they date is not in dispute. You're free to make your own choices on whatever criteria you wish. However personally I feel like if you are too petty with your choices then you'll have struggles with finding people who are suitable mates.

In the case of political views, I do think that someone who has radicalized politics in any orientation will ultimately only be compatible with someone else with identical radicalized political views. Once radicalization takes place, namely the belief in the ultimate moral good of the cause and/or absolutely loyalty to the party above all else for the sake of mankind or some such drivel, is essentially saying that the party is more important than friends and family, which is certainly ones right to believe if they wish, but their friends and family will slowly be alienated unless they are subsequently radicalized into the party. And in terms of romantic interests they will either have to be assimilated into identical beliefs or they will be dumped as simply being uninterested can be seen as just as bad as being the opposition to someone who has radicalized sufficiently.

It's a bit different than differing political viewpoints. I've met a few women radicalized on the abortion issue on both sides. The main issues with dating come down to their beliefs that I'm evil, in the case of dating someone pro-choice, my belief that abortions in cases of sex selection, disease, and very late term abortions have definite moral quandaries that need to be considered leads them to believe that I "hate women" and want them to live under Sharia law. In the case of dating pro-life women they think that my opinions on how it's unhelpful to shame women who get abortions or my admittance that there are circumstances where abortion is absolutely morally justifiable even considering very strict pro-life sensibilities will get me pegged as a baby killer or something equally rediculous.

The main issue is the same that plagues the US in general, people are radically partisan and take political disagreements as personal attacks and their political opinions are a moral crusade which can afford no quarter.

But my dating advice is best described as "don't stick your dick in crazy". Once it's clear the woman loves the party or loves the Church more than she loves you it's time to cut your losses because she will eventually choose them over you.