Any questions about creeping senility were probably put to rest by his sharp attacks on earmarks and his name-dropping catalog of foreign excursions. Now if he could just work on that likability thing.
McCain's repeated use of the phrase "Senator Obama doesn't understand ..." was a key part of his strategy to depict Obama as wet behind the ears, naive, and merely book-smart (while McCain has interfaced with the real world). That kind of contemptuous air of superiority can help you control the debate agenda and possibly even score some points. But does it play with the national populace?
It was reminiscent of Jimmy Carter's merciless offensive against Gerald Ford in their second 1976 debate, when Carter underlined his lack of respect for the incumbent by calling him "Mr. Ford." That debate is remembered mainly for Ford's head-scratching gaffe about Eastern Europe not being controlled by the Soviet Union, but Carter's performance also rubbed many viewers the wrong way that night.
Obama showed discretion and discipline in refraining from ridiculing his opponent over McCain's grandstanding, drama-queen moves to "suspend" his campaign and play peek-a-boo with the debate schedule. Discretion and discipline can be frustrating (especially when McCain leaves so many potential openings), but it's probably a winning strategy, given McCain's short supply of both qualities, and the apparent popular fatigue with some of his antics.