Mediaite's Glynnis MacNicol wins the “credulous nonsense of the day” award with this gem:

Presumably Breitbart is in possession of the entire tape, how else could he release a mere clip and and state so assuredly that Sherrod was making a racist remark if he didn't know the full context.

Seriously? MacNicol can't imagine how Breitbart could make such a claim without knowing the full context? Two obvious explanations should come immediately to mind. If you want to give Breitbart the benefit of the doubt, maybe he just didn't realize it was possible that further context could clear Sherrod? Seems far-fetched, but it's possible. More likely is the possibility that Breitbart is willing to make all kinds of wild, unsubstantiated (and, indeed, false) claims because he knows many people will assume he has good reason for doing so.

If it's the second one, MacNicol just validated his strategy.

To the extent that Breitbart and those like him have power, it is in large part because people who should know better assume that there must be some validity to their claims.