"You can delegate responsibility; you can not delegate accountability."
You are directly responsible for teaching and training those you manage in the performance of their duties, which makes you directly accountable for their failures. Newell, Voth, and MacAllister could not have run the operations without direct assistance of the management in the DC offices of Justice, the FBI, and ATF. The fault ties directly to Holder.
Hussein/Holder have been doing just that for over two years. If nothing erupts by the time of the election, Romney and Boehner will let it slip down the memory hole.