I take all her points, but it seems to me that the meme that is strongest against Obama is the usual Fox-Rove culture war stuff, a way to make Obama seem un-American. Webb destroys that meme and remakes the landscape of the race in ways that hurt McCain.
That is one way to view it, I suppose, but more likely the selection of Webb validates the attack on Obama by acknowledging that there is some sort of liability or vulnerability that Obama had to balance out by choosing Webb. Choosing Webb is another way of saying, “Yes, Democrats must have a military veteran with culturally conservative attitudes on their ticket in order to demonstrate their fidelity to the United States, which is otherwise suspect.” Selecting Webb and selecting him specifically because of what he represents, rather than what he can do, accepts the judgement that Obama’s patriotism and American-ness need bolstering. This has the risk of being every bit as self-defeating and embarrassing as John Kerry’s “reporting for duty” moment at the national convention.