I don't think there's a generalized pattern of the administration folding in the face of right-wing attacks, credible or otherwise. Rather, the issue is that the Obama administration is, and always has been, terrified of engaging on race.I think it's worth considering, but I'm not sure that he's right. On the Shirley Sherrod affair, I think we need more information. Who panicked? Was it someone in the White House communications or political shops (or in the chief of staff's office)? Someone who was on hair-trigger alert to defuse all issues remotely racially tinged as quickly as possible? Or, as we've been told and as I suspect was true, was it someone in the Ag Department -- perhaps someone not very senior in the Ag Department. Perhaps someone who normally goes about his business in one of the many backwaters of the government, someone in a press office whose normal interactions are with equally backwater reporters for the Podunk Times and the Ag Policy Review (uh, those are fictional, I think), and who suddenly found himself fielding calls from the Glenn Beck show and dozens of other major conservative media outlets, and panicked -- followed by more panic from whatever backwater bureaucrat the press official ran to who had the authority to make the wrong decision about Sherrod. If that's the case -- and again, that's my hunch, but I certainly could be wrong -- then it's still possible that race was the trigger, but more likely it was just that a couple of mid-level officials found themselves way over their heads, and any "scandal" about to show up on Fox News would have led to the same outcome.
Chait is right: it certainly isn't true that the administration has folded every time that Beck has singled someone out. I just don't think we know enough yet to be able to conclude why this time was different.