It comes at an important time in this race.

The momentum has clearly shifted from where it was one month ago, right after the Republican Convention. Then, McCain was pushing his way back into the race, as he and Sarah Palin had Democrats on the defensive.

Since then, the trend has been all back to Obama and then some. While Palin has had her share of time in the spotlight, the more likely source of the shift has been the focus on the economy, and the Wall Street Bailout.

McCain did not win points for strategy over the last ten days on the bailout. His move to "suspend" his campaign never seemed to catch fire, especially after the issue went hyper-political in the wake of a testy White House meeting that McCain and Obama attended.

How does McCain get momentum moving in his direction again? Well, the debate this week clearly gives him the chance to do something about it.

One issue that is being raised is that of William Ayers, a founding member of the Weather Underground group, which set off bombs at the Pentagon and Capitol among other places.

Both campaigns furiously battled on Sunday over the issue. Palin accused Obama of "palling around with terrorists." Team Obama fired back that McCain is sliming Obama instead of talking about issues.

Is Ayers a magic bullet for McCain? I'm not so sure, but we'll see if McCain brings it up on Tuesday night.

He needs something to break in his favor.