For candidates who want to prepare for every possible question that could be thrown at them, the format for Tuesday night's presidential debate is slightly terrifying: It is a town hall-style debate, which means that the questions come from uncommitted voters. When political reporters are posing the questions, the candidates usually have a good idea what to expect. But when members of the public get the chance to weigh in, the candidates can sometimes face curve balls that leave them flummoxed.
That's precisely what happened in 1992, when George H.W. Bush was the first to respond to a question about how the national debt has affected the candidates personally. The questioner pressed the wealthy president to talk about his own experience, prompting him to respond at one point, "are you suggesting that if somebody has means, that the national debt doesn't affect them? I'm not sure I get it." Mr. Bush later recovered to some extent, but it was an awkward moment.
And it only got worse: When Mr. Bush finished, Bill Clinton approached the woman and asked, "tell me how it's affected you again?" He then said, in part, "in my state, when people lose their jobs, there's a good chance I'll know them by their names." It was one of those moments that gave rise to the notion that Mr. Clinton was particularly good at feeling the pain of the American people. Mr. Bush, meanwhile, was caught by the cameras checking his watch.
The bad news for Tuesday night's debate is that town hall debates are now more tightly controlled than they were in 1992, when moderator Carole Simpson had no idea what would be asked. This year, moderator Candy Crowley will screen the questions beforehand; that reduces the likelihood of a question that catches the candidates completely off guard.
Here's how it will work: Questions during the 90-minute debate, which takes place at 9 p.m. Eastern Time at Hofstra University in Hempstead, N.Y., will be asked by local uncommitted voters from a variety of socio-economic, racial and political backgrounds selected by the Gallup Organization. Roughly 12 audience members out of about 80 will get to ask questions, with Crowley determining which questions will be posed, and in what order.
Those who want to ask a question write identical versions of the question on two cards and give one to Crowley; if they are selected, they then read the question from their card. Questioners who deviate from the question they said they would ask run the risk of having their microphones cut off, though it seems unlikely that such a step would be taken unless the question is clearly out of bounds.
Despite the fact that the questions will be screened, as they have been since the relative free-for-all of 1992, It's not impossible that a left-field question could get asked. In 2000, for example, George W. Bush was asked during a town hall debate about why he "seemed overly joyed and as a matter of fact proud" of the fact that Texas, where Mr. Bush had been governor, led the nation in executions. (Mr. Bush responded that he was not, in fact, proud of that.)
"You get these questions that are very different than what they would get on 'Meet the Press,' and it also makes it very difficult to prepare when you're doing your mock debates," said Northeastern University professor Alan Schroeder, an expert on presidential debates. "Because who would come up with a question like that?"
Town hall debates, which allow the candidates to roam the stage, also elevate the importance of body language. In the 2000 town hall, Al Gore decided to walk uncomfortably close to Mr. Bush when he was answering a question; Mr. Bush looked over at Gore, nodded, and grinned slightly as he finished his answer. The crowd laughed at the situation - and, to some extent, at Gore's apparent ham-fisted attempt to intimidate his rival - while Mr. Bush came across as natural and good natured.
The format brings specific challenges to both President Obama and Mitt Romney. In the wake of the president's flat, widely-panned performance in the first debate, Mr. Obama's campaign has promised the president will bring more passion and energy to the debate stage while taking more shots at his opponent. But the town hall format makes that difficult: It can look unseemly to turn a question from a struggling voter about how to make ends meet into a political broadside.
"It's definitely harder. You have to finesse it a little more," said Schroeder. "If you're going to lay a glove on the opponent it better be a pretty gentle glove. And you have to attack within the context of the question that the person in the audience asked."
For Romney, meanwhile, the town hall format means he must. Polls show that Mr. Obama is more widely seen as understanding the problems facing average Americans, and the Obama campaign has portrayed the wealthy Republican nominee as an out-of-touch plutocrat with little sense of the challenges the middle class faces. The town hall format, with its direct interaction with voters, gives Romney the chance to reverse - or reinforce - existing perceptions.
Before the 2012 debates, the two campaigns agreed to a "memorandum of understanding" over how this round of debates should be conducted. The Commission on Presidential Debates doesn't sign off on the document, and it is not an official set of campaign guidelines. But the commission is largely controlled by the parties, and it thus tends to follow the rules as laid out in such memoranda.
The 2012 memorandum was not released publicly, but it was obtained and published by Time Magazine. It specifics that the candidates will each get two minutes to respond, followed by additional discussion guided by the moderator - something the Commission has announced publicly. But it also says that "the moderator will not rephrase the question or open a new topic" and goes on to make clear the moderator should remain largely quiet.