Can't help but notice that people who would unfriend someone who has different political beliefs are all the left wing people. People who are more conservative/right of centre/neutral, would not do it.
Bit pathetic that the left wing/Corbynites can only be friends with everyone who agrees that Corbyn is GOD, and that anyone who voted for Brexit is a thick, bigoted moron! 
My dealbreakers.
Racists.
People who are mean and cruel to animals.
People who look down on people and call them 'thick' if they have different political views.
People who think it makes them look more intelligent and seem interesting if they don't like mainstream stuff.
Food snobs. Film snobs. Music snobs.
People who think those who don't cook from scratch are thick/lazy/uneducated.
People who just HAVE to talk about their wealth/ income/ inheritance(s)/ how big their house is/ how much they spent on their last holiday etc...
Bad hygiene.
People who constantly moan about EVERYTHING, and act like no-one has as many problems as them.
People who are constantly late, for no reason, and act like their time is more important that mine.
People who insist on splitting the bill equally, even if they have had £40 worth of food and drink and others have only had a tenner's worth.
I only have a small group of friends - just 3 actually. But they are wonderful friends. Better 3 good ones, than 10 shit ones.