Which brings us to Barack Obama. He has three major vulnerabilities here as I see it. One is his 20-year relationship with the Rev. Jeremiah Wright. Polls suggest he has sustained some damage on this, and it's not clear whether video clips of Wright saying "God damn America" will inflict more in the fall despite the candidate's repudiation of those comments.
Another problem is Obama's relationship with the unrepentant Weather Underground terrorist bomber William Ayers. In an April debate, Obama portrayed Ayers as a casual acquaintance. But Ayers was co-founder of the $49 million Chicago Annenberg Challenge education program and Obama its chairman of the board. The Obama campaign has sued to take off the air ads highlighting the Ayers relationship and tried to intimidate a radio station for hosting a conservative who is examining the Annenberg documents in the Richard J. Daley Library.
Finally, there is Obama's 2003 vote against a bill, "virtually identical" as the Obama campaign admits, to one that passed the U.S. Senate 98-0, banning the killing of fetuses who have survived abortions.
Liberals like Obama tend to go over the line between positions and associations that most voters find reasonable (though they may not agree) and those they find outrageous. They assume, usually correctly, that mainstream media will be reluctant to report on the latter, as has been the case in all those mentioned above. Conservatives take more care to separate themselves from the outrageous because they know mainstream media will pounce on them if they don't.
On Ayers, the Obama campaign has tried to suppress discussion. But it will likely fail. The emergence of new media and the First Amendment mean that is like stopping the Mississippi River from flowing to the sea. If I were advising Obama, I would tell him to confess error, as he arguably has on Wright, on both Ayers and the Born Alive Protection Act, lest they cause his campaign as much damage as the furlough ads caused Michael Dukakis and the Swift Boat ads caused John Kerry.