The format for Tuesday night’s presidential debate is expected to be a challenge. Neither Obama nor Romney has sparkled in town hall meetings.

President Obama and Mitt Romney will go head-to-head Tuesday in their most challenging debate format: the town hall, where they will field questions from more than a dozen undecided voters sitting a few feet away as millions of Americans watch from home.

Both men have held dozens of town halls with voters over the years, yet neither has sparkled in that setting. Each is cool and cerebral, often seeming more comfortable behind a lectern.

The event in Hempstead, N.Y., moderated by CNN’s Candy Crowley, will put them in a format tailored to produce interaction with voters, rather than heated exchanges with each other that fire up their supporters. The setting was introduced in the 1992 race between the famously empathetic Bill Clinton and the famously detached President George H.W. Bush, producing a sharp contrast that helped set the course of that race.

The imperatives now are different. Obama must remain presidential, while also showing some of the fire and flash that was missing at the first debate in Denver. Romney, who has been cast in advertisements by the Obama campaign as a wealthy and heartless chief executive, must show that he could be a competent commander in chief, but also one who could relate to the average voter.

Democratic supporters want Obama to come out swinging. Message received, say campaign aides, who promise that he plans to rebound sharply, casting Romney as dishonest about his positions.

But aides and others close to the campaign acknowledge the hurdles ahead — some inherent in the upcoming format, others in the candidate himself.

Obama ranks somewhere between Clinton and Bush on the empathy scale. He can be more focused when speaking directly to a voter, rather than a camera. As a candidate on the trail in 2008, he showed himself able, if not exactly gifted, when it came to listening and connecting.

Still, the same problem that tanked his first debate performance could dog his second. He is still a sitting president who practices the art of the stem-winding answer, as well as a former law professor who has found it hard to shake his academic demeanor.

“When he is on during a town hall, he can be very on and engaged,” said a person close to the Obama campaign who asked not to be identified while talking about the president’s challenges. “The risk is the same tendency to give professorial responses. He has to show he connects.”

Obama relied on the town hall format during his first bid for the White House. He tried to continue the sessions early in his presidency, but eventually backed away from them. Security requirements meant the crowds had to sit farther away from him, and from the perch of the White House, unplanned moments were riskier and made it harder to control the message.

The Hofstra University debate will be tightly controlled, but those close to the president hope it will play to his strengths. He likes being close to his audience, one noted, where he can gauge how his message is resonating.

Impromptu moments aren’t typically a problem for Obama. His asides tend to be self-deprecating.

When Obama and Republican rival John McCain were asked in the 2008 town hall debate, “What don’t you know? And how will you learn it?” Obama didn’t skip a beat. “My wife, Michelle, is there and she could give you a much longer list,” he said to laughs. “And most of the time I learn it by asking her.”

Four years later, the bar for Obama is much higher. Just being likable and
well-versed on the issues might not be enough to reignite his campaign. He’s going to be expected to land some blows.

Obama “allowed Mitt Romney to dance away a week ago,” said Sen. Richard J. Durbin (D-Ill.), who pointed to Vice President Joe Biden‘s aggressive performance in his debate against Rep. Paul D. Ryan as a model. “We learned a lesson. I learned from it. I’ll bet you the president learned a few things too.”

Romney has had more than his share of hard lessons this campaign. Most often his missteps have come in unscripted, town-hall-style moments. But those events also have shown off his best attributes — helping him win over primary crowds with his intellect, his command of the issues and what voters who saw him in person often described as his presidential aura.

Early on, Romney’s advisors tried to put him in intimate venues — a coffee shop or a diner where he sat down with small groups of voters to hear about the problems they faced. Many of those discussions were fruitful, arming him with stories to tell later on the stump about Americans’ woes in “the Obama economy.”

But unfortunately for Romney, there were memorable moments like his June 2011 visit to a Tampa, Fla., coffee shop, where he attempted a joke after listening to unemployed voters talk about their job searches. “I should tell my story,” Romney said. “I’m also unemployed.” The group laughed, but the quote still haunts his campaign.

Six months later, at a question-and-answer session with voters in Nashua, N.H., he uttered another line that would be mercilessly taken out of context by opponents. Arguing that his healthcare plan would encourage more competition among insurance providers, he added that when disappointed, “I like being able to fire people who provide services to me.”

The town hall settings also revealed Romney’s harder edge, a practicality that endeared him to some voters but turned off others. In Ohio, when a young student told him she was drowning in loans, he told her that students could not rely on government to pay their education costs, and said his best advice was to “shop around” — a remark that quickly became an attack line for the other side.

Romney has had much more recent practice in the town hall format than Obama. He has smoothed some rough edges when interacting with voters and, just in the last few weeks, has opened up more with his audiences about people he has helped through his work in the Mormon Church, and the stories that have touched him most on the campaign trail.

That combination of a crisp debate showing and his effort to connect seems to be working for the former Massachusetts governor. Last week, his favorable rating reached 50% for the first time among registered voters in the Pew Research Center survey.

But Romney and his advisors know that sustaining those gains could hinge on his performance Tuesday night — at a town hall.