Let's be clear on what Obama's task was in this first debate:
With a big advantage as the preferred candidate on the economy, Barack simply needed to convince the 10% of the country that is looking for a reason to vote for him, that he would not give up the house as President, that he was "capable enough" to keep us safe.
Obama did that easily - he closed the case on his judgment, he was commanding on facts and figures, he came off as a rational and clear thinker, he did not have any gaffes, and he went right at McCain on all his errors over the last 8 years ("You were wrong, John...").
Let's be clear on what McCain's task was tonight:
With the economy the top issue in voters' minds and this debate being the only one focused on national security, McCain needed to make a strong closing argument that (1) he was, by virtue of his experience, the only rational choice in a dangerous world, and (2) that Obama would in contrast be a huge risk. And argue these so strongly that it would eat into his deficit in the polls. McCain needed a game changer.
And on that task, John McCain failed totally. He was unable to put Obama away on any of Obama's perceived weak points - the "negotiation without preconditions" issue, the surge issue, and attacking Pakistan. He had two major gaffes - calling Pakistani prime minister Asif Ali Zardari, "Kadari" and Pakistan "a failed state, and an awkward moment when he couldn't pronounce "Ahmedinejad".
He also did not answer Obama's strongest counterpunch on McCain's "preconditions" attack, when Obama pointed out that both Henry Kissinger and the Bush Administration disagreed with McCain.
Temperament
There was another factor at play here, and that was temperament. Kennedy arguably beat Nixon in 1960 (in the first televised presidential debate ever) largely because he came off as young and vigorous and Nixon came off as sickly and grouchy.
Obama's body language conveyed openness, strength, respect (even friendship) for McCain, and a cool and cheerful demeanor. He had a lot of zingers. He looked McCain in the eye. He smiled often, especially at McCain's jabs.
McCain smiled only once, when he was clearly angry at Obama's questioning his judgement on Iraq. He was hunched and never once either addressed Obama or looked at him. He seemed contemptuous and dismissive. He sneered and grimaced a lot.
Do not underestimate the power of those unseen cues in influencing voters' final decisions on the candidates.
That said, Obama had some lost opportunities tonight. He did not tie George W. Bush around McCain's neck tightly enough, especially on the Iraq/Afghanistan issue. He also lost a great opportunity to deck McCain on one of his biggest distortions - that he will take care of veterans. McCain's record on caring for our veterans is spotty and inconsistent at best.
Also, keep in mind that to the extent any undecided voters feel Obama is weaker on foreign policy than McCain, remember who Barack's running mate is.
Now, try that with McCain. (Where is Sarah, by the way? Nobody can find her...)
Read more at my blog, Daily Chai.