Well, I wonder if your friend isn't also wondering the same thing yellowflowers? 
Thing is, a lot of us as students were socialists, and life seemed black and white back then. I even joined the SWP and regularly fought with my father for voting Tory.
Now I am older, have different concerns and beliefs, life has changed me. I now vote Tory, ds goes to state school, but nothing to do with supporting the local school. It's oversubscribed anyway. I just cannot afford private fees right now. I would love to think the state offered a world class education, but the evidence says otherwise. A friend from my student days hung the phone up on me last year during a debate about the election.
I was bemused. But each to their own. I did wonder if friends cope deal with these opposing beliefs, as they are really quite fundamental.
Anyhow, my friend got back in touch recently, only took a year to calm down and get it in perspective! She had reason to go to court, and the local labour councillor let her down repeatedly. She confessed the Tory counsellor from the next town took up her case and helped her immensly, so it was ok to be friends with the likes of me 
Honestly, I have bigger things to worry about.