Robert McNamara just passed away, getting nearly the same amount of attention that Michael Jackson has been getting. Ok, one second's worth of MJ attention, despite the fact that McNamara had a huge impact on US foreign policy as SecDef, on the world as head of the World Bank, and on reconciliation/forgiveness as he spent his post-SecDef life trying to make up for the mistakes he made.
I show his documentary, Fog of War, in my Intro to IR class on a regular basis. He not only tried to explain why he did what he did, but desperately wanted to educate leaders, present and future, so that they avoid his mistakes, which included a significant amount of arrogance. Reviled by the military for his micromanagement, bringing in a group of inexperienced but not at all humble whiz kids into the Pentagon, the parallels to Rumsfeld are easy to make. A younger McNamara actually looked a great deal like Rummy, so when I show the movie, it is hard not to think about the Rumsfeld era.
But there is a huge difference between the two: McNamara realized he had made some mistakes, sought belatedly to try to correct them, and tried to learn from them. Rummy has yet to show any real remorse or any realization that he might have erred. [Indeed, in the final act of the Harry Potter novels, Lord Voldemort retains the possibility to un-break his soul if he just demonstrates some remorse, but does not].
I also believe that McNamara did less harm than Rummy--because the military of the 1960s was not going to fight the war in Vietnam any better without him interfering. Rummy, on the other hand, has blazed a very visible trail of bad decisions that made things significantly worse, from cutting the number of MP battalions that were supposed to go to Bagdhad to keeping a very low force cap in Afghanistan in 2002, which helped to make Anaconda a lost opportunity.
Perhaps I would be as angry at McNamara had I been politically aware at the time, but I doubt it. McNamara had the chance to have a second and third act in his life, and he made much of them.