He realized that his interview 2011 with Donald Rumsfeld when he was plugging his memoirs was absolutely awful, allowing Rumsfeld to evade all responsibility for his lies and crimes. I panned Stewart for that interview at the time and said that it was symptomatic of a general failing of his, that he seemed to let politically powerful people off the hook when he was talking directly with them, unlike when he was taking about them in their absence.
With Rumsfeld, as part of the general revisionist attempts by the Iraq warmongers and enablers to avoid blame for that disaster, now suggesting that he had misgivings about the Iraq war right from the beginning, that gives Stewart the chance to expose that lie and he does so.
But Stewart also says that he has learned a lesson from that interview and similar debacles, that even if he does manage to corner these people and show them to be liars and frauds, that provides only a momentary catharsis, that they and others like them in the future will continue to lie in order to try and persuade the country into future disastrous wars.
But that does not mean that we should cease our efforts to stop them from continuing to do great harm. Maybe one day we will succeed.
(This clip aired on June 11, 2015. To get suggestions on how to view clips of The Daily Show and The Nightly Show outside the US, please see this earlier post. If the videos autoplay, please see here for a diagnosis and possible solutions.)