One way of looking at Shirley Sherrod's firing is to classify it with all the other rhetorical fights we've had over the past few years that are more about offense, than practical issues. I think that's wrong, and it misses precisely why it's important to take a stand.
Shirley Sherrod brought to the Obama administration a deep understanding of the very issues that the USDA has grappled with for years--discrimination among them. She knew the lay of the South, and had been grappling with the problems of agriculture, literally, all her life. It was in her blood. Firing her robs the administration of a great resource, but more importantly it robs the people who she was appointed to serve.
Thus the Obama's administration strategy here is not simply a reatreat in the face of racist inversion (as bad as that is), it's a retreat from defending the livelihood of Americans in need. Many of those people, possibly most of those people, are not black. Racist inversion, like the racism it springs from, is a cluster-bomb. Being white gets you a running start, but it does not get you in the clear.