Half the time Tories (and other non-socialists) don’t seem to realize they are doing it. I find in some places (e.g. blogs on the Middle East, Labourlist) self-identifying as a leftist means you’re “asking for it”, being told you’re a sheep, you don’t understand economics, and that’s the politest comments. And MP’s are perfectly fine calling people fruitcakes, loonies, Trotskyite entryists, etc. I think we leftists have to stop being polite and stand up for what we believe in i.e. decency and human dignity.