Tonight at 9pm Eastern, Barack Obama and John McCain will face off for their third and final debate at Hofstra University in Hampstead, New York. The rules and format look fairly similar to the first except that they will be seated at a table with Bob Schieffer (no wandering around the set for McCain? Damn!) and they'll get to give 90 second closing statements. Another difference: this debate will focus exclusively on economic and domestic issues.

I think it's safe to say that expectations at this point are pretty low for McCain who has proven himself a less than capable debater, especially against Barack "iceman" Obama. As for what McCain's tack tonight will be, he has famously said both that he intends to "whip Barack's you know what" and that Obama can expect that Ayers will come up. But the people surrounding McCain have various versions of what to expect tonight.

McCain spokesman Tucker Bounds:

"In starker terms than any previous debate, the country will be able to see the difference between Barack Obama's brand of leadership and John McCain's record of reforming government, working across the aisle and delivering for America," McCain spokesman Tucker Bounds said. "It will be a more spirited debate than the other three because the stakes are higher and both candidates are going to be eager to explore their differences."

McCain spokeswoman Nicolle Wallace:

In an interview on NBC's "Today" show this morning, McCain spokeswoman Nicolle Wallace said the senator from Arizona would focus tonight on what she called "the truth about Barack Obama's plan for raising taxes" and his pursuit of other "liberal" policies. "Barack Obama is measuring the drapes," she declared. "He and Nancy Pelosi and Harry Reid are planning a liberal Democratic takeover of our economy." She referred to the speaker of the House and the Senate majority leader.

GOP consultant Alex Castellenos:

"I think Sen. McCain... will say not that you don't know Barack Obama but you do," Castellanos said. "He's going to tax. He's going to spend. What happens if Democrats in Washington and a Democratic president get together and spend and tax without restraint, with no one to stop them -- no adult supervision?

"Make the case that's relevant to voters," Castellanos added. "Talk about risk that way but don't talk about risk... 20 years ago."

In other words, all over the map.

As for Obama's pre-debate talking points, well that's easy since they were leaked to press earlier today (Ben Smith has them.) Much of them focus on the message that "McCain is erratic, Obama is steady" but they also make clear that Obama is going to use the debate to promote his new Rescue Plan for the Middle Class.

* Over the course of the campaign, Barack Obama has laid out a set of policies that will grow our middle class and strengthen our economy.

* But he knows we face an immediate economic emergency that requires urgent action -- on top of the plans he's already laid out -- to help workers and families and communities struggling right now.

* That's why Barack Obama is introducing a comprehensive four-part Rescue Plan for the Middle Class -- to immediately to stabilize our financial system, provide relief to families and communities, and help struggling homeowners.

* This is a plan that can and should be implemented immediately.

* Obama has shown steady leadership during this crisis and offered concrete solutions to move the country forward and his Rescue Plan for the Middle Class builds on the plans to strengthen the economy and rebuild the middle class that he's laid out over the course of this campaign.

As for which John McCain will show up tonight, I've long since given up trying to predict that although I think we can safely predict that, if his debate prep consultants have anything to say about it, he'll be doing a lot more looking both Barack Obama and the audience at home in the eye and he'll probably say "middle class" about as much as he usually says "my friends."

Update [2008-10-15 19:0:11 by Todd Beeton]:More from David Axelrod.