Me too, but I'm sure Glenn knows the difference. In the rough and tumble of the interview, I chalked it up to a slip of the tongue.
The point of it, of course, was that the communist gasbag seemed unaware that the Nazis were socialists. Notice Glenn's swipe at Wikipedia too? Funny stuff.
It was funny - I like his show. He needs to get a mike for the RA in the background, though, so the audience can hear the responses.