It takes a special sort of stupid to think the left has moved "to the center" over the past decade or two. (top right) That's just plain retarded.

It is retarded, but makes sense with one assumption that most of them are making. They tell themselves "I am a rational, kind, average person, I must be a centrist, or maybe center left". And then they leap off the cliff while still claiming to be near the center and then wonder "why is everyone else far right?!?!"