RUSH: This is an Obama ad, a new ad. It’s not a PAC ad. This is a campaign ad. Obama is approving of Harry Reid’s message essentially. This is an Obama ad suggesting that Romney didn’t pay any taxes.

OBAMA: I’m Barack Obama and I approve this message.

ABC’S DAVID MUIR: Was there ever any year that you paid lower than the 13.9%?

ROMNEY: Well, I haven’t calculated that. I’m happy to go back and look.

ANNOUNCER (sinister whisper): Did Romney pay 10% in taxes, 5%, zero? We don’t know. But we do know that Romney personally approved over $70 million in fictional losses to the IRS as part of the notorious Son of Boss tax scandal, one of the largest tax-avoidance schemes in history. Isn’t it time for Romney to come clean?

RUSH: Ah, Son of Boss! Son of Boss. Here we go again. It looks like somebody’s going to have to explain what a Son of Boss is. You know what Son of Boss is? Be careful. Don’t go to wiki on it. (It will only screw you up.) I’ll explain it in due course. But it was a tax-deduction scheme, and it was legal but it didn’t look good. I will bet you that this Son of Boss thing is one of the things they’re linking to the idea they’re trying to put forward that Romney didn’t pay any taxes.