Taking a look at the guidelines the two campaigns have agreed upon for tonight's townhall style debate, there is little hope for any fireworks or spontaneous moments. The two campaigns' debate negotiators have made sure of that.

From Lynn Sweet:

Tuesday's match-up at Belmont University in Nashville, Tenn., will be moderated by NBC's Tom Brokaw, with the questions to be culled from a group of 100 to 150 uncommitted likely voters in the audience and another one-third to come via the Internet. The Gallup Organization -- as in past debates like this -- has the job of making sure the questioners reflect the demographic makeup of the nation.

Brokaw selects the questions to ask from written queries submitted prior to the debate, according to the "contract."

An audience member will not be allowed to switch questions. Under the deal, the moderator may not ask followups or make comments. The person who asks the question will not be allowed a follow-up either, and his or her microphone will be turned off after the question is read. A camera shot will only be shown of the person asking -- not reacting.

While there will be director's chairs (with backs and foot rests), McCain and Obama will be allowed to stand -- but they can't roam past their "designated area" to be marked on the stage. McCain and Obama are not supposed to ask each other direct questions.

The media can't seem to discuss this debate without insisting that the forum favors McCain. He is the self-professed townhall king, after all, having challenged Barack to a crapload of these things this summer.

The Obama campaign is, rightly, playing up these expectations.

When it comes to sheer format, we enter today's debate the decided underdog.  John McCain does extremely well in town hall settings. It's been his favorite format throughout his career and we think that he will of course do very well.

The McCain campaign for their part is previewing the tone McCain is likely to strike tonight.

McCain, 72, will try to leaven his attacks with humor, said Republican campaign aides, some of whom plan to wear cufflinks with a mock Obama presidential seal. McCain and his surrogates will be ``aggressive truth tellers'' on debate night, said senior adviser Nicolle Wallace. ``I don't accept the premise that that makes the campaign negative.''

And while McCain's demeanor is likely to be a big improvement over his first debate performance, honestly, having seen McCain in action at these townhalls, part of his thing is having a dialogue with the questioner and taking follow-up after follow-up, as if to say "see, I'm not afraid of your stinkin questions." He won't be able to do that tonight. Also, no one talks about how good Barack Obama is in these townhalls. If he is stiff in debates, in townhall settings he's much looser; the interaction allows his personality to come through more.

All of that having been said, I do suspect that McCain has lowered the bar for his performance to such depths that the whole expectations game might actually be a wash. While McCain's insistence on a series of townhalls should signal that the McCain campaign sees the format as a strength, the fact is people think the Democrats have done better than the Republicans in the debates.

By a 21 point margin, 50%-29%, voters said the Democrats had the debate edge over rival Republican running mates John McCain and Sarah Palin, while 10% of respondents said the two tickets were equally as good and 4% said neither was good.

That is likely to carry over into expectations for Barack tonight.