Whodunit?

One of the fun parts of any political campaign scandal is trying to figure out who leaked the thing to the press.

Speculation over who leaked such details as we now know about Herman Cain's sexual harassment settlements as CEO of the National Restaurant Association seems to be centered around whether the leak came from the Romney campaign or the Perry campaign.

My guess -- and I think we'll know at some point whether I'm right -- is that it came from either the Bachmann campaign or ... the Cain campaign.

Here's my cui bono logic:

- Romney is running neck and neck with Cain in Iowa. If he was behind this, it would have come out right before the Iowa caucus, so that Cain wouldn't have time to respond, and so that former Cain supporters wouldn't have time to coalesce around another candidate. If this thing came from the Romney camp, it was a rogue supporter, not a campaign operation.

- Perry is intentionally and specifically dialing back expectations in Iowa. He's not a contender there, so he's writing it off and focusing on later states. The best outcome for him would be for Cain to go into Iowa strong and hurt Romney badly there. It makes no sense at all for this thing to be coming from the Perry campaign.

There are two candidates who stand to benefit most, and one who stands to be harmed least, by this thing happening when it happened.

Michele Bachmann and Ron Paul are both behind Romney and Cain in Iowa. This could help either or both of them, but if so, they need a few weeks to capitalize on it. In other words, the timing is perfect for them.

The whole thing isn't really Paul's style, but it is Bachmann's.

Iowa is, realistically, Bachmann's last stand. She romps there or she is out either that night or right after the New Hampshire primary. Paul's in it for the long haul regardless, because that's just how he rolls.

Finally, at least one DC lobby ("Concerned Women for America") that seems to be in the tank for Bachmann was primed and ready with pointed questions for Cain on the very evening the story broke.

Bachmann is the prime suspect. She has the most to gain, she's the most desperate to get back into contention, as a female she's best positioned to capitalize on allegations of another candidate's misogyny, and her backers seem to have been prepped to exploit.

The only other possibility I see is that the Cain campaign brought this thing out themselves. They knew it was going to come out some time in the next 12 months, and this was the least bad time for it to do so -- with their man on top and with several weeks to do damage control before the Iowa caucus. Better now than on the Friday before Super Tuesday, or on the last Friday in October 2012.