Joining Harvard professor Henry Louis Gates Jr., Cambridge cop Sgt. James Crowley and President Obama was a fourth “surprise guest” at last week’s “beer summit”: Vice President Biden.

Given that the scheduled attendees looked more awkward than Sen. Robert Byrd at the NAACP Image Awards, Biden’s presence made lots of sense. If you were Obama, wouldn’t you want an oxygen-sucker such as Joltin’ Joe to Hoover through all those painful silences with a vomit of words?

No doubt, Obama figured: It doesn’t matter what he has to say, so long as he keeps talking long enough for the press to get its photo-op without Crowley tasing Gates or Gates flipping over the table to shout, “Do you know who I am?” Biden could just simply switch on his mouth’s autopilot and jibber-jabber about Iraqi Kurds, socket wrenches, gay basset hounds, Social Security, World War II, World War II-and-a-Half, World War II-and-Three-Quarters and whatever else popped into his mind. Anything to eat up the time would do.

This theory’s appeal lies in that it’s very hard to figure out what Joe Biden is doing in the Obama administration in the first place, especially since every time he lends the benefit of his experience and insight, the White House corrects him.

Obama’s entire campaign was predicated on “turning the page” and bringing a “fresh start” to politics. In particular, Obama insisted that his opposition to the Iraq war was more than merely prescient; it illuminated his superior judgment and fresh thinking.

Yet, when tasked with his “first presidential decision” – as the cliché about veep picks goes – he went with Biden, who voted for the Iraq war before he opposed it and who represented the quintessential business-as-usual senator (his main backers were a credit card company and trial lawyers).

Obama said he picked Biden for his unparalleled foreign policy experience and, “above all,” because Biden was “ready to step in and be president.”

Six months later, it’s doubtful anyone is any more keen on the prospect of Biden becoming president. Still, Biden does have a strange new respect from many on the right as the administration’s unwitting “truth-teller.” Recall, it was Biden who admitted that the White House “misread how bad the economy was.” He told ABC’s George Stephanopoulos that if Israel felt it necessary to take out Iran’s nuclear program, there was nothing the U.S. could do to stop it. This “green light” for Israel was so off script from administration policy, it might as well have been dubbed in, Kung Fu-movie style. Biden recently branded the Russians the sick man of Europe and pooh-poohed the idea they’re anything like our strategic equals. The Russians flipped out like Skip Gates at a traffic stop, and Hillary Clinton was dispatched to scoop up Biden’s rhetorical, er, mess.

Biden is a likeable fellow, which is why even his detractors cringe with fear when they hear him talk. And, unlike the unflappably smooth president, there’s something human about Biden. When he talks, it’s as if he’s just slightly disoriented, like he just woke up from a nap and doesn’t know exactly what he’s saying yet.

That widespread empathy is probably why Obama opts for head-patting condescension toward his No. 2 man. During his address to Congress in February, Obama announced that Biden would be put in charge of ensuring the stimulus wasn’t wasted and he would be super-terrific at it because, “Nobody messes with Joe.”

But there’s still a problem. Yes, Biden is occasionally a truth-teller. But, just as often, he’s explaining how FDR spoke to Americans on TV, years before they had television sets or – give it time – how squirrels would taste more like ice cream if goats were only taller. And again, whenever he punctures the politics as usual with an inconvenient truth, the administration forces Biden to recant, not the other way around.

And that helps put Biden in perspective. Obama, the agent of change, picked a well-worn fixture of the political establishment mostly for crass political reasons: to win votes among blue-collar whites, particularly in Pennsylvania, to defuse charges that Obama lacked experience, and to conjure up an un-Cheney (on that score, they succeeded).

Supporters insisted that Biden lent gravitas to the ticket, but as Slate’s Mickey Kaus rightly put it, Biden never had gravitas, only seniority. Six months into his vice presidency, that hasn’t changed much. But in an administration obsessed with message control, he stands out like a sitcom character miscast in a political thriller, a useful reminder that Obama’s promises to transform Washington were always overblown.

And that’s why his surprise guest role at the beer summit was so heartening. Finally, his talents were perfectly matched for the job: Providing nothing of substance – at great length! – to a photo-op designed to be substance-free in the first place. Expect Biden to lend his own patented Bidenosity at similar events in the future, including the Six-Party Beef Jerky Conference, the U.N. Jagermeister Shot Forum, the Hooters Colloquium and anywhere else he can be of service.

© 2009 Tribune Media Services, Inc.