I said it when President Bush did it and I'll say it when President Obama did it - this essentially places the Administration in power above the law. This is everything but an outright admission of guilt/culpability.
Shy of not having the best candidate ever, I think this will be disastrous for Obama's reelection. I think this turns off the average American, and maybe even makes him or her a little mad. I don't think it was the smartest move ever, and honestly Holder ran the department, so at the end of the day he needs to reap the consequences, right or wrong. This denies that justice.