MacsMind discusses John McCain's cheap shot at Rumsfeld. This is not going to go over well among GOP primary audiences. Reason one is because Rumsfeld was one of the more popular figures in the Administration among the GOP's base. The second reason is that McCain's claim that Rumsfeld was one of the worst Defense Secretaries ever is just not true.
Louis Johnson and Bob McNamara both were far worse. One also can take a good look at Les Aspin as well. James Forrestal wasn't exactly doing a fine job, either. Other SecDefs never faced major challenges, like those under Eisenhower (Charles E. Wilson, Neil McElroy, and Thomas S. Gates). Rumsfeld, in his second-go-around, did face challenges and dealt with them. We started the Global War on Terror with eight regimes that sponsored terrorism (the Taliban in Afghanistan, Saddam's regime in Iraq, Iran, North Korea, Libya, Sudan, Cuba, and Syria). When Rumsfeld left, three of those regimes no longer did so.
In McCain-World, that is mismanagement. I don't think so.