They couldn't implicate top Generals for Abu Ghraib what the hell makes them think they can pull down Rumsfeld?
They've already pulled down Rumsfeld. And they couldn't implicate top Generals because 'the Powers that Be' were standing in their way.

Those powers that be ain't so powerful anymore. Sure, lawyers will get rich but heads will roll. They may not be able to throw the most powerful of them in jail, but they're still going to drag their balls through the coals.