What's the name for someone who...?

doesn't like people whose opinion differs from theirs? I have a friend whose sister is a feminist, vegan, anarchist and other things I don't care to remember, anytime anyone has an opinion that doesn't match hers regarding any of these things she acts like she's so much better than them and they're all idiots she will not listen to or acknowledge them. It winds me up and I'm sure there must be a name for people like her, thought this would be the place that would know, also this may be in the wrong category I had no idea where to put it sorry