In tonight's debate, John McCain seems set to "go there" on Ayers, goaded into it by Obama's plainly saying that McCain had until now been too chicken to say it to Obama's face.

It's quite possible Obama has a range of rebuttals ready. It's not as if he doesn't have plenty of examples of McCain's dodgy friendships to choose from. He's also probably hoping McCain loses that famous temper, messily, on live TV in front of millions - the obvious followup being ads of McCain snarling and the simple question "would you trust this man with America's nukes?"

But McCain also has another problem with "going there" - sheer hypocrisy from his campaign. As Bill Scher points out, Rick Davis penned a Boston Globe op-ed back in 2004 in which he urged Bush and Kerry to pressure their supporters not to engage in smear campaigns. He wrote as campaign manager for McCain's failed primary bid, which crashed after a Bush camp smear about McCain having fathered "an illegitimate child who was black. In the conservative, race-conscious South, that's not a minor charge."

It's not necessary, however, for a smear to be true to be effective. The most effective smears are based on a kernel of truth and applied in a way that exploits a candidate's political weakness.

...Campaigns have various ways of dealing with smears. They can refute the lies, or they can ignore them and run the risk of the smear spreading. But "if you're responding, you're losing." Rebutting tawdry attacks focuses public attention on them, and prevents the campaign from talking issues.

Back then, Davis described such smear campaigns, designed to keep voters from considering candidates stances on the issues, the "blackest of the dark arts". Don't you just love the smell of sheer hypocrisy in the morning? McCain's connection to his lobbyist chums are certainly far closer than Obama's to Ayers.

We got a preview of how tonight might play during the primary debates:

Crossposted from Newshoggers