I think Colbert was using Euphemism rhetoric. By using a statement like "I didn't say she's a Nazi,  I said there is no difference between what the two do," it sounds less offensive then straight up calling that person a Nazi.There's an obvious bias in the clip. He seems to be taking sides with the democrats by focusing how Fox news was calling democrats Nazi's. In the clip, he only talks about how republicans are judging democrats, but in reality both democrats and republicans call each other names. Now is his point valid? I would probably say yes because republicans are sometimes harsh on their opponents. Take the incident in Arizona over the past few weeks for example. People were saying Sarah Palin, during her campaign, had signs that said shoot and kill or whatever and someone actually took her word for it and shot the congress women. I'm not sure if that's true or not but thats what "democrats" are saying. As you can see, both sides take aim at each other.