Here's the question: Would Americans be offended if a white pastor had blamed 9/11 on The United States? Yes -- in fact, the regrettable former rector at my church did the same thing, and his congregants were appalled. Would some (at least) Americans be taken aback at the news that a candidate's close confidant (and spiritual advisor) had said, "God d**n America"? Of course.
All this has taken a toll. One anecdote: A close friend of mine, a moderate Republican who was initially receptive-to-enthusiastic about the Obama candidacy recently wrote me, "I'm rethinking it after this Wright thing. And his wife is now proud to be an American for the first time? Forget her." If some white voters are turning from Obama, it's not because of his skin color. It's because of the views of those closest to him -- and what they suggest about the candidate's own views.
Just for the record: It's not Obama's Republican opponents who have made an issue of his race -- or who have most damaged his candidacy. It's his closest compatriots (like Wright and Mrs. Obama) and his intra-party competitors (like Clinton).