He didn't.
Both candidates came out of the gate nervous, visibly affected by the pressure. Ten minutes in, Sen. McCain looked much stronger than he had in the previous two debates, and after 20 minutes I thought he clearly was outperforming Sen. Barack Obama. About that time, Sen. McCain said,
"The whole premise behind Sen. Obama's plans are class warfare...."Invoking that right-wing chestnut had almost no effect on Sen. Obama or the conversation. Just saying it seemed to embolden Sen. McCain, however, and a confident fighter pilot began to unravel into an irascible old man.
As Sen. McCain became more combative, Sen. Obama took the cue to become less so. The result was a McCain advantage in the first 30 minutes, perhaps a draw in the middle third of the debate, and Sen. Obama finishing stronger, clearer and noticeably cooler.
Although Sen. McCain's seething got in the way of his ability to connect with the audience, this was by far his best showing in the presidential debates, largely because he was more assertive throughout. The GOP nominee's strongest moment, without a doubt, was his dismissive response to Sen. Obama linking him to the Bush administration.
His downfall was in slipping from assertive to aggressive, as if he grasped neither his present disadvantage nor the reasons why his numbers have eroded steadily over the last few weeks.
He also seemed to be unaware that while Sen. Obama was speaking, his own reactions would be displayed on the other half of a split-screen image. Reminiscent of the angry Bob Dole of 1996 and the "sigh" that arguably cost Al Gore a 2000 presidential debate, Sen. McCain made no effort to mask his disdain, even contempt.
Derision may play well with partisans and hard-line conservatives, but it alienates undecided and independent voters. Among that group, few will be swayed by attempts to associate Sen. Obama with Bill Ayers or ACORN, or even parrying relentlessly over "Joe the plumber."
I'm not saying that Sen. McCain violated some code of propriety or political correctness. Winning is about being effective, not simply palatable, and once again Sen. McCain stubbornly refused to do what works.
Attacks don't win presidential debates. Clever "ah-HA!" barbs don't win debates. And for all of our table-pounding insistence that candidates be specific, details alone don't win debates, either.
Debates, especially this election year, are won with inspiration and aspiration -- sad commentary on an unthinking electorate and yet indisputable political reality. Sen. Obama has seized that reality, and Sen. McCain has sought to counter with fear and doubt. Historically, those tactics have been reliable, but they haven't worked well in 2008.
They certainly didn't work last night.
So what's Sen. McCain to do, now that he's 0-for-3 in the debates and faces an all-but-insurmountable deficit in the polls?
It's a simple choice, really. He can stick with his attack strategy, which will soil his legacy and damage other Republicans' chances on November 4th -- or he can take a deep breath and do the honorable thing for his party.
I know what "the old John McCain" would do. I'm just not sure he's still around.