We’re going to see a lot of spot polling done in the first blush of the debates, but it’s helpful to remember two historical points about their effect.  First, it’s difficult to know what will resonate from any one debate.  In the first few hours after the Jimmy Carter/Ronald Reagan debate, for instance, pundits believed that Carter had won the debate by sounding more presidential and Reagan not specific enough.  It wasn’t until after a couple of days that people realized how badly Reagan beat Carter, and that the most resonant portions of the debate were “There you go again” and Carter taking advice from his 12-year-old daughter.

This debate didn’t appear to offer any absolute victory moments to either side, and like in 1980, it will probably take a few days for the resonant exchanges to solidify in the public mind.  Barack Obama’s repeated variations of “John is right” will get a lot of play, as will John McCain’s “Senator Obama doesn’t understand”.  Obama’s final address was probably his best moment of the debate, but since it came right out of his stump speeches and his 2004 Democratic Convention address, it’s not likely to surprise too many people.

Some may point to the foreign-policy portion for moments that will resonate for McCain, but no one expected Obama to beat McCain on foreign policy anyway.  Obama needed to keep up with McCain on foreign policy, which he ultimately failed to do with his fabrications on Kissinger and meeting terrorist-supporting heads of state without “preconditions”, but that more or less followed expectations.

The most powerful resonant moment for McCain didn’t even involve him.  Jim Lehrer, referencing what will be a massively expensive bailout plan, asked both candidates what they would cut in order to pay for it:

As president, as a result of whatever financial rescue plan comes about and the billion, $700 billion, whatever it is it’s going to cost, what are you going to have to give up, in terms of the priorities that you would bring as president of the United States, as a result of having to pay for the financial rescue plan?

McCain offered a freeze on discretionary spending, and hammered the point that he had been trying to rein in government spending for his entire career.  Obama, on the other hand, offered a laundry list of spending increases.  Here is the entire answer:

OBAMA: Well, there are a range of things that are probably going to have to be delayed. We don’t yet know what our tax revenues are going to be. The economy is slowing down, so it’s hard to anticipate right now what the budget is going to look like next year.

But there’s no doubt that we’re not going to be able to do everything that I think needs to be done. There are some things that I think have to be done.

We have to have energy independence, so I’ve put forward a plan to make sure that, in 10 years’ time, we have freed ourselves from dependence on Middle Eastern oil by increasing production at home, but most importantly by starting to invest in alternative energy, solar, wind, biodiesel, making sure that we’re developing the fuel-efficient cars of the future right here in the United States, in Ohio and Michigan, instead of Japan and South Korea.

We have to fix our health care system, which is putting an enormous burden on families. Just — a report just came out that the average deductible went up 30 percent on American families.

They are getting crushed, and many of them are going bankrupt as a consequence of health care. I’m meeting folks all over the country. We have to do that now, because it will actually make our businesses and our families better off.

The third thing we have to do is we’ve got to make sure that we’re competing in education. We’ve got to invest in science and technology. China had a space launch and a space walk. We’ve got to make sure that our children are keeping pace in math and in science.

And one of the things I think we have to do is make sure that college is affordable for every young person in America.

And I also think that we’re going to have to rebuild our infrastructure, which is falling behind, our roads, our bridges, but also broadband lines that reach into rural communities.

Also, making sure that we have a new electricity grid to get the alternative energy to population centers that are using them.

So there are some — some things that we’ve got to do structurally to make sure that we can compete in this global economy. We can’t shortchange those things. We’ve got to eliminate programs that don’t work, and we’ve got to make sure that the programs that we do have are more efficient and cost less.

Where in this answer does anyone find a single spending reduction?  This is nothing more than a shopping list of Democratic spending priorities.  Obama never once specified a cut he would make, even after Lehrer asked the question three times.

That hit on Obama’s turf.  That was an unexpected win for McCain, and if it sticks, could be the resonant moment he needs.

Otherwise, I don’t think this debate will move the needle much one way or the other.  Undecided voters will probably stay that way through the third debate, closer to the election.  McCain needs to remain aggressive and press Obama on spending, national security, and foreign policy.  The overnight polling on these debates will be essentially meaningless, absent some major gaffe.