In a novel theory, Illinois Sen. Dick Durbin now says the scandal might be that there was an implicit, corrupt deal to keep the non-fired attorneys in place. So it wasn't the firings but the non-firings that are the potential outrage. Lately, Democrats also have focused on the missing Rove e-mails from his Republican National Committee account, figuring that if they are missing, they ipso facto are part of a cover-up of something or other.
The U.S. attorneys inherently are political positions. They serve at the pleasure of the president and often are recommended by senators. This obviously doesn't mean that they should be partisan in their administration of justice, but they must share the administration's law-enforcement agenda, and the reasons for their selection might have a lot to do with politics.
The most troubling firing is that of New Mexico U.S. Attorney David Iglesias, whom Republican Sen. Pete Domenici complained prior to the election wasn't pursuing a corruption case against Democrats quickly enough. If his termination was for explicitly partisan reasons, that would be inappropriate, but a senator complaining about a U.S. attorney is not in itself a scandal.
Whatever the wrongdoing is supposed to be at this particular moment in the U.S. attorney controversy, it no doubt will change. As he maneuvers to keep the story alive, let's just hope Chuck Schumer keeps his hold on reality.