An argument pushed by the campaign of Sen. Hillary Clinton, D-NY, is that Sen. Barack Obama, D-Illinois, has not been fully vetted.As Clinton-backing Pennsylvania Gov. Ed Rendell told us last week "she's been really well vetted, all the bad stuff is by and large out there, and there are no surprises. With Sen. Obama I think the right now he may run, a little stronger in some areas -- not the key states -- but in some areas against Sen McCain, but understand that he hasn't been vetted." Rendell said there was 10% about Clinton that "we don't know yet" and "about 50% about Barack Obama that we don't know yet."Which brings us to William Ayres.Ayres is Distinguished Professor of Education and Senior University Scholar at the University of Illinois at Chicago, and founder of both the Small Schools Workshop and the Center for Youth and Society.He also spent the 1970s as a fugitive from justice, as a member of the Weather Underground, after the domestic terrorist group, preparing to attack an Army base, accidentally exploded a Greenwich Village townhouse killing three of their own members. Ayres later married feather Weather Underground member Bernardine Dohrn, then on the FBI's 10 Most Wanted List.''I don't regret setting bombs,'' Ayres told the New York Times in 2001 upon publication of his memoir about that era, "Fugitive Days." ''I feel we didn't do enough.''As celebrated members of the Chicago liberal world, Ayres and Obama have some connections.They served on a board together when Obama was a state senator. Ayres donated $200 to Obama's campaign in 2001. They sat on a panel together in 2002 called "Intellectuals in Times of Crisis." Obama went to Ayres and Dohrn's home in 1995 to be introduced to some of the more influential liberals in the area by the state senator he was preparing to succeed, Alice Palmer.(Palmer, who changed her mind about not running for reelection for her state senate seat after being defeated in a US House race, was later unable to get on the ballot because Obama challenged her petitions to do so, in some hardball Chicago-style politics, a whole other interesting story.)"Bill Ayers lives in his neighborhood. Their kids attend the same school," Obama senior strategist David Axelrod told the Politico. "They're certainly friendly, they know each other, as anyone whose kids go to school together." (Ayres' kids are actually much older than Obama's but Dohrn is still active at the school.)"We can relitiigate again and again these 40-year-old battles," Axelrod said. "He thinks what was done then was wrong and outrageous, and he believes that you can’t defend the indefensible – but he’s looking forward, he’s not looking back.""Senator Obama strongly condemns the violent actions of the Weathermen group, as he does all acts of violence," Obama spokesman Bill Burton told the New York Sun when asked about the connection. "But he was an eight-year-old child when Ayers and the Weathermen were active, and any attempt to connect Obama with events of almost 40 years ago is ridiculous."Is that enough for you? Perhaps it is. Perhaps you think this is all a silly political smear.But should Obama get the nomination, what will moderate and swing voters in Ohio, Pennsylvania, Michigan and Missouri think of it all? Will they think Obama is able to transcend partisan divisions if he's been supported by Ayres?The proverbial Republican attack machine is chugging along on this -- see THIS CLIP from last night's "Hannity & Colmes" on Fox News, featuring Karl Rove making much hay out of this connection, however tenuous, and Ayres speaking at the University of North Dakota saying he doesn't regret anything he did against the government.There is a tendency in the Obama campaign to not take these types of stories seriously. That is a "perfect world" approach to politics. In a perfect world, some might argue, we would be debating policy in Iraq, the economy and health care. We wouldn't have discussions about whether Al Gore claimed he invented the internet, or George W. Bush got a DUI in the 1970s, we wouldn't talk about Swift Boat Vet for truth claims that contradict official Naval records.But that's not the world we live in. Yes, the mainstream media is complicit in that, but there are other forces at play. Paid TV ads, the internet, cable news, talk radio -- sources of information, and misinformation that have an impact on the electorate, necessitating that the mainstream media cover stories having an influence on the election even if they did not originate in the mainstream media. We of course are obligated to fact check them and deal with them responsibly and the mainstream media does not always rise to the challenge.But campaigns have to know how to deal with such stories as well.Former Sen. John Edwards, D-NC, has not endorsed Obama precisely because he worries Obama is not tough enough to deal with attacks such as these, such as the fact that this Ayres story is still out there, with very little pushback from Obama -- or even, frankly, any acknowledgment as to why some voters might not like the idea of Obama being friendly with a man such as Ayres.This Stevenson-esque (Adlai, not McLean) regard for fighting these stories is likely a reason we haven’t seen a stampede of superdelegates over to Obama to end this never-ending primary season.What do you think?