MSNBC's Morning Joe hosted Rudy Giuliani this morning to talk about Mark Sanford's affair; Brzezinski conducted the first 3:20 of the interview, and participated in the rest. Right at the very beginning, Giuliani turned the discussion to another famous politician caught in an affair:

Giuliani “Let's look at Bill Clinton.”

Brzezinski: “Yeah.”

“Yeah,” Brzezinski responded. Not “Well, with all due respect, maybe we should look at you.”

In fact, neither Brzezinski nor any of the other journalists present ever brought up Giuliani's own high-profile affair(s), even as Giuliani made several comments that would seem to invite such questions:

Giuliani: “I don't want to mention all the names, because you just revive, you revive, I can give you a big list of Republicans, a big list of Democrats, issues like this have come up.”

Giuliani: “We have an equal number of people who get into trouble. For every Republican, we can name a Democrat who has the same kind of trouble.”

Brzezinski and the others kept saying the really important thing is whether government funds are used in the affair. That might have been a good time to ask Giuliani about New York taxpayers paying for a security detail for Giuliani's mistress. But Brzezinski gave no indication whatsoever that the politician she was interviewing about politician affairs involving taxpayer funds was a politician who had an affair involving taxpayer funds. Instead, she let him attack Bill Clinton.

And yet Mika Brzezinski thinks there is a double standard that benefits Democrats when it comes to political affairs. That's what she was arguing just a few days ago. As I explained in my column on Friday - and as Brzezinski inadvertently proved today - there is a double-standard, all right. But it isn't what she thinks it is.