The left is doing what they do best; dismiss an issue, calling it irrelevant because it could reflect poorly on their judgment, their character and their policies. There is however, some "there, there" in this case and regardless of how frantically the left whines about Republicans playing politics with this issue, it isn't going to go away, much to their chagrin.
The left was relentless surrounding the Valerie Plame issue when no crime or cover-up was ever committed. They went bonkers over Abu Ghraib and indicted the whole of the U.S. Military as miscreants and perverts. Now, when there is a very real issue that resulted in the deaths of Americans by enemy combatants, they just want everyone to shut up. Good luck with that!