Have you ever stopped being friends with someone over differences in political views? Are there any issues that are so important to you that you cannot be friends with someone who holds a contrary opinion?
Yes, according to some definitions of friendship.
There are two ways that I generally stop being friends: loss of contact for prolonged time when the other person is not bothering to attempt to keep contact, or an outright breach of politeness, on my part or theirs, which results in a cessation of engagement.
On the other hand, when someone who is an acquaintance who maintains a social/society friendship, I feel no qualms about reducing my estimation of that relationship to "association" all the way out to "I know this person" and possibly to "this is my dearest enemy, we see each other only to continue to confirm our mutual loathing."
Although thankfully nobody has quite gotten the latter.
