WASHINGTON (Reuters) - Republican presidential candidate Mitt Romney has seen a surge in opinion polls and voter enthusiasm since his strong debate performance against President Barack Obama on October 3.
With Obama and Romney running neck-and-neck in the polls, much will be at stake in the debate Tuesday at 9 p.m. EDT (0100 Wednesday GMT) in Hempstead, New York.
Here are five things to watch for in the candidates' second of three matchups before the November 6 presidential election:
Obama's dour, passive performance two weeks ago frustrated many of his liberal supporters. Even Obama himself acknowledged that he was, as he put it, "overly polite."
He will have to show more conviction this time. Aides believe Romney got away with soft-pedaling conservative positions that could alienate moderate voters in the first debate, and they aim to prevent that from happening again.
"There's no doubt he's memorizing more deceptions as he prepares for Tuesday's second debate," Obama campaign manager Jim Messina wrote of Romney in a memo.
Obama could also try to paint Romney as an out-of-touch plutocrat who does not care about the middle class.
Expect Obama to bring up Romney's reluctance to release more than two years of personal tax returns, his career as a private equity executive at Bain Capital, and Romney's disparaging remarks about the "47 percent" of Americans who pay no federal income taxes.
Vice President Joe Biden set the table with an aggressive, sarcastic performance in his debate last week against Republican vice presidential nominee Paul Ryan, but Obama will have to show more gravitas.
"It's up to him to find that happy medium between maybe the bombast of Vice President Biden's personality and the lackluster performance (Obama) gave in the last debate," said Linda Peek Schacht, a former spokeswoman for Democratic President Jimmy Carter.
Conventional wisdom holds that debates generally don't affect the outcome of presidential races.
That may not be the case this year. Romney's strong performance in the first debate wiped out Obama's lead in opinion polls and boosted enthusiasm among the former Massachusetts governor's fellow Republicans. Romney is now viewed as more credible than Obama on many of the economic issues that are paramount to voters.
This time, Romney won't benefit from low expectations.
He will have to show a command of the issues and a sense of empathy with voters who still view him as less likeable than Obama.
In recent weeks, Romney has been weaving personal stories into his stump speech, both his own and those of people he has met on the campaign trail. During last week's debate, Ryan pointed out that the unemployment rate in Biden's hometown of Scranton, Pennsylvania, is now higher than when he and Obama took office in January 2009.
Expect Romney to continue this more personal approach, both as a way to win voters' sympathy and to show solidarity with the hardship that many Americans have experienced since the financial crisis hit in 2008.
"Lofty rhetoric is one thing, but there are some cold, hard truths at the street level. That will be a big component of how this debate goes," a Romney aide said.
This debate adds a significant element of uncertainty: actual voters.
Instead of the usual podium-and-moderator format, Obama and Romney will field about a dozen questions directly from undecided voters in a "town hall" setting, moderated by CNN political reporter Candy Crowley.
The format tends to reward candidates such as former President Bill Clinton, who could connect with voters on a personal level. It also could force the candidates to tone down their aggression and explain how their policies would personally help those asking the question.
Neither the aloof Obama nor the stiff Romney is known for having a particularly warm personality.
Obama is seen as more likable than Romney by a wide margin, according to Reuters/Ipsos polling data, but his charisma on the campaign trail may not transfer to the town hall format.
"I think (Obama is) still under the gun. He seems to be better with an audience of thousands when he's giving a speech than he is in the debate format," said American University political science professor James Thurber.
Foreign policy was expected to be a big advantage for Obama, who can point to the end of the Iraq war, the killing of Osama bin Laden and plans to wind down the unpopular Afghanistan war.
But the death of four Americans during an attack on a diplomatic facility in Libya last month has given Romney a chance to question Obama's leadership.
The administration's account of the incident has shifted over the past several weeks, and there are questions about whether security concerns were ignored.
Biden may have created an opening last week when he said the administration did not know the diplomatic compound had asked for more security, contradicting the testimony of two State Department officials the day before. The White House has distanced itself from Biden's remark.
Romney initially was criticized for politicizing the incident, but he has stepped up his attacks on the campaign trail.
Expect Obama to point out that Romney's fellow Republicans in Congress have backed deep spending cuts that would likely lead to less money for diplomatic security. Romney could counter by saying the administration has wasted money in other areas that could have been redirected toward security spending.
At a time when 23 million Americans are either unemployed, underemployed, or out of the work force, neither candidate has offered more than a vague outline of the steps they would take to boost economic growth and employment.
Obama has offered few new ideas since the Republican-led House of Representatives rejected a package of infrastructure spending and state aid a year ago, while Romney has yet to fully explain how he would manage to cut taxes without adding to the deficit.
The job-creation goals they have outlined are very modest. Romney's promised 12 million new jobs are likely to materialize on their own if the economy grows as projected, while Obama's promised new jobs in manufacturing and natural gas likewise are projected to materialize without government help.
The town hall format could force Obama and Romney to explain in greater detail what they would do to goose the economy beyond the sluggish path that forecasters foresee in the years to come.
"I think you will find that sometimes citizens are better at pushing for specifics than maybe a moderator would be," Peek Schacht said.
Editing by David Lindsey and Doina Chiacu