When President Obama and Mitt Romney take the stage Tuesday for the second presidential debate, they will carry with them the results of the first. Here are some questions and answers about what to expect at Tuesday's high-stakes rematch at Hofstra University on Long Island, N.Y., which comes 20 years after the first presidential town hall debate.

Q How will the format differ?

A While the debate will take place over the same 90-minute time frame, the questions will come from undecided voters in a town hall setting. CNN's chief political correspondent, Candy Crowley, will moderate.

Q How can I watch it?

A All of the major networks and cable channels will broadcast the 8 p.m. CDT debate.

Q What policy areas will be tackled?

A Unlike the first one, which was limited to domestic policy with a heavy concentration on the economy, the Hofstra debate will cover both domestic and foreign issues.

Q When was the first town-hall style presidential debate?

A It was on Oct. 15, 1992. The second presidential debate that election year, it featured President George H. W. Bush, Gov. Bill Clinton and Texas businessman H. Ross Perot in Richmond, Va. In it, Bush told Clinton he was concerned Clinton would turn the White House into the "Waffle House" with his changed positions on critical issues. But Bush stumbled when he was asked by an audience member, "Has the national debt personally affected each of your lives?" Part of Bush's response was "I'm not sure I get it. Help me with the question and I'll try to answer it ... Everybody cares if people aren't doing well."

Q What is the quality of questions posed by regular citizens compared with those by journalists?

A Michael Nelson, a professor of political science at Rhodes College in Memphis who has written 25 books on the presidency and elections, says the quality is good. "I like the town hall questions," Nelson said. "They are a little less predictable than the questions asked by professional journalists and, as a result, they can take the candidates out of their well-rehearsed comfort zones."

Q Why are third-party candidates excluded from the debates?

A The Commission on Presidential Debates, a nonprofit organization that has conducted the debates since 1988, has established a rule that a candidate must show 15 percent support in at least five national polls to be eligible for a podium on the televised stage. In 2012, Green Party candidate Jill Stein, Libertarian Party candidate Gary Johnson have requested to be included. Johnson, who will be on the November ballot in 48 states and has sued for access, argues that any candidate who is on enough ballots to win the required 270 Electoral College votes to win the White House should be permitted to participate.

Q How many people are expected to watch the second debate?

A An estimated 67.2 million watched the first debate in Denver, but we're still in the midst of Major League Baseball playoffs season with Game 3 of the American League Championship Series set for the date of the Hofstra debate. Nelson said interest in the first debate was "unusually high." He said "a lot of people will tune in for the second debate to see if Obama has gotten his game back."

Q How many states will already have begun early voting by the time of the second debate?

A More than 800,000 people have already voted. And Indiana, Idaho, South Dakota, Georgia, Vermont, Maine, Iowa, Wyoming. Nebraska, Ohio, California, Montana, New Mexico, Oregon, Washington and Arizona will have begun in-person early voting by Tuesday. Ohio -- where nearly 1 in 5 voters have already cast ballots -- is the biggest prize among the swing states on that list.

Q When is the final debate?

A The third debate will be held Oct. 22 at Lynn University in Boca Raton, Fla. It will be limited to foreign policy and will be moderated by CBS' Bob Schieffer.