The question for John McCain these days from me, if I had a chance to ask one, would run something like this: “OK, old man, what’d the kid ever do to you – walk across your lawn?” Such is the manner of the McCain campaign here in early August that I would really like to know. What did Barack Obama ever do to him?

Let’s be clear. It’s not about being able to take an elbow – or a roundhouse right. Those things happen when vying for the presidency. My question is about the bizarre lack of maturity emerging on the part of McCain’s campaign ad people. In the last week, we’ve had to watch spots comparing Obama to Paris Hilton (not even Perez, for God’s sake!) and Britney Spears. They’ve also tried to make some totally Martian inference that Obama considers himself to be something called “The One.” Dude. That’s just weird.

The risk McCain runs with openly juvenile outbursts is enormous. Questions and attacks on his mental stability cost him the GOP nomination in 2000. While it’s unlikely Obama would ever unleash the tirade of venom Bush the second uncorked against McCain then over alleged emotional instability, it all remains out there in the ether. McCain’s poor choices in ad content, if continued, are sure to bring all those nasty fumes coiling back around his own head again in a matter of time. This should be the last thing his hyper-muscular message team wants, yet they seem determined to play with fire – even at the risk of leaving their own candidate in a smoldering heap of ashes. It is, to say the very least, an interesting tactic. But it looks desperate, if not addled, which makes it a poor political choice for an aging candidate who has been known for decades as an extreme hothead. Obama’s been fairly smart in responding, if a little choppy. But he recently made a serious mistake. He allowed himself to be cornered into a race discussion, which he should have dismissed.

In the wake of McCain’s notorious Spears/Hilton ad, Obama resurrected an oft-used stump line that gets huge laughs in the lily-white Bible belt: among an escalating series of GOP scare tactic points, he warns his audience with mock seriousness, ... “and I don’t look like the other presidents on the currency…” The line works well for Obama, who delivers it in standup comic mode – breezy, relaxed, and ready to take on all comers. Crowds love it, even in states that haven’t yet turned fully in his direction.

Hearing it one too many times, and apparently not amused by the laughter of the audiences, McCain’s team of advertising hotheads jumped on him for it last week. They flatly accused him of playing the race card and dealing it “from the bottom of the deck.” This was a patently loony attack, but Obama made the mistake of treating it as an assessment that had something behind it. He should have dismissed it out of hand, with more laugh lines. This would have been incendiary to all the short fuses running the McCain message machine – and that’s the strategy Obama needs to get working on. Tick them off, and let the cranky, outlandish, and downright scary fireworks fly. McCain is his own worst enemy, especially when he’s in a fit of pique. Obama has many simple ways to drive McCain into that corner, and he needs to focus on them between now and Labor Day.

Instead, he gave them a foothold by trying to give the questions on race a serious answer. In the current context, there is no serious discussion on race possible or desirable, so all Obama did with his response was open a tiny crack in which McCain might gain purchase with his nuttiest arguments: Obama is a risk to the country, he is different, and we don’t know what that difference might really amount to yet, now, do we, America? Are you willing to take a chance on this unknown quantity?

The only way to beat an argument like that is to sneeze it away as the insignificant puff of nonsense that it is. Americans know times are dire. We need a president with some actual thoughts in his head. McCain, having lived in George W. Bush’s shirt pocket for the last few years, is not a person who can muster the originality we need. Nor can he generate the energy, the dynamism, the very real vigor needed to reignite America’s own vigor, innovation, and epic optimism. McCain, as Obama rightly said at the end of this very ugly week of politicking, is running for our most revered office on the paltry fuel of cynicism. And cynicism, at this delicate point in America’s history, is little more than a shovel with which to dig our own grave. Americans simply don’t want it. They want rebirth, re-emergence as the full, free, and decent country we have been at our best. Obama, clearly, can get us there. McCain, who seems to be channeling Ebenezer Scrooge before the ghosts arrived, cannot. Americans will see this, once they start paying closer attention after Labor Day. Obama, in the meantime, has to do his best to belittle McCain’s unworthy attacks in the one acceptable way at his disposal – through the vehicle of humor. If he succeeds, he will have a clearer path to election in November. If he fails, he risks being defined by McCain before people take the time to get to know him. With stakes so high, it’s a risk he can’t afford.