I compare this election to a job interview. The employers (that’s you, Mr. and Mrs. America) are sick to death of the current job holder (that’s my team, the GOP). They are itching to fire us.

But they cannot do it until they have found a plausible alternative. Now if the alternative gives offense or embarrasses himself at the interview—if he somehow shows himself unacceptable—then the employer will have no choice: He’ll have to struggle on with the current incumbent for a little longer.

If, however, the alternative behaves himself—if he says the right things, if nothing disgraceful can be found in his resume—then the job is his.

So (to repeat something I said in my very first column in this space) Barack Obama’s most important challenge in this race was to make himself boring. He needed to leave behind the soaring rhetoric and grand themes of the primary campaign and act the part of a responsible, level-headed president-in-waiting.

Watching Tuesday’s presidential debate—possibly the most boring presidential debate in history—I can only say: mission accomplished.

Meanwhile, McCain careens from mistake to mistake.

McCain’s job in this campaign was to stay cool. He had to recognize: “Look, by all rights I should lose this thing. But you never know. Obama is inexperienced, over-educated, and likely to be perceived by many voters as exotic, even alien. Over months of electioneering, he’s bound to stumble. When he does, I’m here—a steady pair of hands—to pick up the pieces.”

But staying cool in the face of downbeat polls requires tremendous discipline. The natural temptation is to Do Things—to Change the Game!

Hence the Palin nomination. Hence the campaign suspension. Hence the misleading negative ads.

The problem is that the more a candidate Does Things, the more likely he is to make a mistake—to frighten off voters at the very moment he needs to be reassuring them. That is what has happened to McCain. Whatever else you say about his campaign, it’s not boring!

The McCain campaign has depicted Obama as a dishonorable slanderer of American troops, a friend of terrorists who is thrusting sex upon kindergarten children. Spicy stuff. (It certainly got a reaction from Shrum.)

But then we see the actual Obama on stage—and he sure does not sound spicy. He sounds grave and measured. He speaks respectfully of John McCain. He finds something nice to say about George W. Bush. You can almost hear swing voters across America thinking, “He’s polite. He’s presentable. He seems less jumpy than the old white guy. He’ll do.”

I’m not sure that McCain’s negative advertising was ever meant to be believed. I think it was meant to provoke.

McCain may have hoped to do to Obama what George W. Bush did to him in the famous South Carolina primary of 2000: get under his skin in a way that goads him into a self-destructive outburst. If Obama had lost his temper, if he had even complained, he would have been done for. America is ready for a lot, but it’s not ready to hear a young, Harvard-educated black man criticize a white war hero.

But then—Obama doesn’t have to criticize him, does he? He can follow the advice of another white war hero, Napoleon Bonaparte: Never interfere with an enemy in the process of self-destruction.