In fighting [the left] I became like them. Against my own instincts, against my own knowledge against everything I know to be right and wrong, I descended to their level when I used those two words to describe Sandra Fluke. That was my error...and I feel very badly about that.
Later in the show, Limbaugh used the whole thing as a pivot to explain why he thinks Democrats should apologize to him. There's a running transcript over at Business Insider.