It would depend on the situation with that person.

But people are allowed to choose friends based on whatever criteria they want, even if it seems petty or closed-minded to others. Sometimes a single difference in opinion is impactful enough to damage a relationship.

If one of my friends sincerely believed that video games were so harmful that they were willing to vote in favor of banning them despite knowing I play video games, I don't think I'd remain friends with that person for long. I'm sure that's how some people feel about friends that are on the different ends of the political spectrum. Each side sincerely believes in what they're supporting, but that can lead to irreparable conflicts of interest in friendships.

However, I disagree with a mass and impersonal "If you support ____ unfriend me now".

I have unfriended people because of political differences. But they were all people who I wasn't close with anyways, and likely people who I would never meet in real-life anymore either. For people I am genuinely friends with, I usually just "Unfollow" them so I don't have to see any of their FB posts anymore.

It depends. Political alone, no. Social issues tied in? Yes. I don't need oppressive, bigoted people as friends etc.

It has nothing to do with politics.

If you support Trump's racist ideals, then I don't want you on my friends list because you're a racist.

Likewise if you support Hilary's BS and lying, then I don't want you on my friends list because you're a lier.

This reminds me of the close friends and famous actors ,Jimmy Stewart and Henry Fonda , they had a life long friendship despite Henry being a well known Democrat with strong liberal views and Jimmy an equally well known Republican.When asked about this both said they never discussed politics with each other.
My thoughts on the matter is I don't carry a list with me detailing the criteria needed to be a friend or not, It tends to be very organic and just happens overtime by itself , Having said that social media is differentif some one continually brings up a subject that I don't appreciate and can't find common ground, I would ask them not to direct it at me . if it continued and I used facebook then yes I would unfriend them. after all a friend on facebook seems from some one who is a non facebook user to be a very loose term.

Depends.

I have a hard time befriending zionists, people who favor one race over another, and assholes who make fun of others.

I recall a dude who talked with me for a bit in high school. All was well until he started being a dick to the disabled kids and called them retarded, said they're better off dead, etc. I said he can go fuck himself and ended any sort of relation we had.

Really no point in cutting ties if it's a small difference. for example, I am fine with high taxes while many people arent. should I hate them and never talk to them? no, as neither one of our viewpoints are oppressive or hateful 

Obviously I would care if one of my friends voted for Adolf Hitler but I felt like that was an extreme parallel to use so I didn't spend much time acknowledging it originally. I just thought that so many people were grouping up everyone under the guise of "well if you do this it can only be because you think or believe this" which I remember being against because it basically acted as though everyone was one singular entity instead of being able to think or have their own reasons for doing something and that generalizations like that were only going to make things worse for everyone. Just like how I had originally said I thought the act of voting didn't necessarily mean you agreed with everything Hillary or Trump said 100% but it's a lot more complex than that.  Voting is certainly an action though.

Edit: I've edited this comment to rewrite it as to more accurately portray what I meant to say at the time, as the original was poorly worded. 

See the way I see it, part of the "person they are" is their values. I wouldn't want to affiliate with somebody whose values were repugnant to me.

Some of my friends are probably closer to if not completely on the right-wing of the political spectrum, but it's not like they are unreasonable or unlikable. I think it's OK to disagree with friends on things. Discussion and debate can keep relationships alive and warm.

I have though chosen to unfollow people on social media before, probably because seeing regressive leftist propaganda every once in a while being spammed by people you have respect for is annoying.

I agree with that. We should all have personal standards that we hold not only ourselves to but the people we surround ourselves with. I was under a weird misconception due to things I had been first introduced to that somehow voting wasn't the same thing as doing the action yourself because voting didn't necessarily mean agreeing with everything of the person you were voting for, but it's certainly more complicated than that. 

Edit: I've edited this comment to rewrite it as to more accurately portray what I meant to say at the time, as my original was worded poorly.