The "cut off" happens in Christianity too, but not done in hate. You could consider it an act of love especially for the healthy ones who are uninfected by evil from infected person.
The cut off is like isolating an infected person from the rest, but the isolated person isn't allowed to rot away. He/she is isolated to heal while being voluntarily "reeducated" with the holy Bible.
this sort of cut off especially in the religious sense sometimes pose the question on what true family is all about because in some religion, it even gets to the point where a father can kill his child or even watch his child being killed just because he believes in another religion. truth is that it is hard to watch someone that is close to you join in a contrary part that is against all the things you stand for but completely isolating the individual or even causing harm to the person is on the extreme.
politics is not a cult and often times, what a political party believes in officially doesn't reflect in what every member of the party believes in. today, a democrat might be a core supporter of his party and tomorrow he might just change and join he republican party. there is better way of selling the idea of your party to a brother or a family member other than making him feel like a stranger just because he doesn't align with your party system. in the typical Nigerian society were the people's democratic party and all progressive congress are the two main parties that most persons belong to, there is always a fine line between politics and every other form of relationship. when it it times for politics you play politics and when the season is over you go back to your normal activity and leave out all the sentiment.
But when people at the wrong side are isolating you, instead of you isolating them, it could be considered a self isolation which they do ignorantly for your good. Besides, humans or animals with dissimilar behavior naturally "isolate" themselves. And that could help keep things be more peaceful, prevent the whole from getting spoiled or let people with similar abilities come together to solve problems they are uniquely equipped to solve
even if you are on the right side of the divide, the fact that you can't relate well with your homies just because of different ideology is going to cause you some psychological issue that might progress into natural hatred with time.