If Sanders and Warren were telling the truth, they'd argue FOR, not against, the TPA.

[cui bono]

195. Yes, people try to use them as insults, just as people try to use liberal as an insult.

But they are really just political descriptions.

I don't see how the post you linked to is using it as an insult rather than a description. The fact is both parties have moved right quite a bit on the political spectrum so that now the centrist position is pretty much moderate Republican. Obama himself is a self described moderate Republican. That's just what it is. The Republican Party is now extreme right wing and the Dem Party is for the most part centrist, the party leadership certainly is. It used to be left/liberal, fighting for unions, SS, the environment, etc... now, not so much.

I have seen Turd Way used and emoprog/firebagger used, both of which I feel is using a label as an insult, but then those are modified labels so it's pretty clear what the intent is.