Sens. Barack Obama and John McCain clashed repeatedly over the causes and cures for the worst economic crisis in 80 years Tuesday night in the second presidential debate. Moderated by NBC's Tom Brokaw, the meeting took place at Belmont University's Curb Event Center in Nashville, Tenn.

The audience was selected by Gallup, the polling organization, and was split three ways among voters leaning toward McCain, those leaning toward Obama and those undecided. Brokaw chose from thousands of questions submitted by audience members in person, and on the Internet. Here are some highlights of the questions and answers.

What's the fastest way to fix the economy?

The state of the economy is "a final verdict on the failed economic policies of the last eight years, strongly promoted by President Bush and supported by Sen. McCain," Obama said. The fastest fix began with passage of the $700 billion bailout package, he said, followed by "tax cuts for the middle-class" and changes in health care insurance and the energy systems to reduce the "enormous burden on families."

"I have a plan to fix this problem and it has got to do with energy independence. We've got to stop sending $700 billion a year to countries that don't want us very -- like us very much," McCain said. "We have to keep Americans' taxes low. All Americans' taxes low. Let's not raise taxes on anybody today," and added, "We obviously have to stop this spending spree that's going on in Washington. Do you know that we've laid a $10 trillion debt on these young Americans who are here with us tonight?" (Watch Video: Fix The Economy)

How will the bailout package actually help people?

"This rescue package means that we will stabilize markets, we will shore up these institutions. But it's not enough. That's why we're going to have to go out into the housing market and we're going to have to buy up these bad loans and we're going to have to stabilize home values," McCain said.

Obama said bailout package ought to losen the credit brunch, since, "right now, the credit markets are frozen up and what that means, as a practical matter, is that small businesses and some large businesses just can't get loans. If they can't get a loan, that means that they can't make payroll. If they can't make payroll, then they may end up having to shut their doors and lay people off." (Watch Video: Bailout Help Me?)

How can we trust either of you?

"I understand your frustration and your cynicism, because while you've been carrying out your responsibilities -- most of the people here, you've got a family budget. If less money is coming in, you end up making cuts," Obama said, before pinning the blame for crisis on the Bush administration, supported by McCain. "When George Bush came into office, our debt -- national debt was around $5 trillion. It's now over $10 trillion. We've almost doubled it."

McCain said, "I can see why you feel that cynicism and mistrust, because the system in Washington is broken." Then he offered what he called his record of reform, saying, "I have advocated and taken on the special interests, whether they be the big money people by reaching across the aisle and working with Sen. [Russ] Feingold [D-Wisconsin] on campaign finance reform, whether it being a variety of other issues, working with Sen. Lieberman on trying to address climate change." (Watch Video: Trust You?)

Health care, energy, and entitlement reform: which comes first?

"I think you can work on all three at once," McCain said. However, "ware not going to be able to provide the same benefit for present-day workers that that present-day retirees have today. We're going to have to sit down across the table, Republican and Democrat, as we did in 1983 between Ronald Reagan and Tip O'Neill."

"We're going to have to prioritize, just like a family has to prioritize," Obama replied. "Energy we have to deal with today, because you're paying $3.80 here in Nashville for gasoline, and it could go up. And it's a strain on your family budget, but it's also bad for our national security. ... Health care is priority No. 2. ... And, No. 3, we've got to deal with education so that our young people are competitive in a global economy." (Watch Video: Your Priorities?)

What sacrifices will Americans have to make?

After the Sept. 11, 2001 terrorist attacks, "President Bush did some smart things at the outset, but one of the opportunities that was missed was, when he spoke to the American people, he said, 'Go out and shop,'" Obama said. "I think the American people are hungry for the kind of leadership that is going to tackle these problems ... There is going to be the need for each and every one of us to start thinking about how we use energy. ... I'm interested in doubling the Peace Corps."

"We're going to have to tell the American people that spending is going to have to be cut in America. And I recommend a spending freeze that -- except for defense, Veterans Affairs, and some other vital programs, we'll just have to have across-the-board freeze," McCain said. "I'm going to ask the American people to understand that there are some programs that we may have to eliminate." (Watch Video: What Sacrifices?)

How can we move faster toward a green economy?

"We have an issue that we may hand our children and our grandchildren a damaged planet," McCain said, pointing out that he broke with the White House over climate change legislation. "I introduced the first [climate change] legislation, and we forced votes on it. That's the good news, my friends. The bad news is we lost. But we kept the debate going." What's the best way of fixing it? "Nuclear power," McCain said.

"It is absolutely critical that we understand this is not just a challenge, it's an opportunity, because if we create a new energy economy, we can create five million new jobs, easily, here in the United States," Obama said, calling for investments in solar, wind, geothermal. "It can be an engine that drives us into the future the same way the computer was the engine for economic growth over the last couple of decades." (Watch Video: Go Green Faster?)

Is health care a responsibility, or a right?

McCain said he thought health care insurance was "a responsibility" that Americans should have to shoulder themselves, and not a right. "We should have available and affordable health care to every American citizen, to every family member. "Let's have community health centers. Let's have walk-in clinics. Let's do a lot of things to impose efficiencies," including making online medical records the universal standard, he said.

Obama continued, "I think it should be a right for every American. In a country as wealthy as ours, for us to have people who are going bankrupt because they can't pay their medical bills -- for my mother to die of cancer at the age of 53 and have to spend the last months of her life in the hospital room arguing with insurance companies because they're saying that this may be a pre-existing condition and they don't have to pay her treatment, there's something fundamentally wrong about that." (Watch Video: Health Care A Commodity?)

How will the economy affect the military?

"I don't understand how we ended up invading a country that had nothing to do with 9/11, while Osama bin Laden and al-Qaida are setting up base camps and safe havens to train terrorists to attack us," Obama said, while at the same time praising U.S. troops for their performance in the Iraq war. "It has put an enormous strain on our budget. We've spent, so far, close to $700 billion and if we continue on the path that we're on, as Sen. McCain is suggesting, it's going to go well over $1 trillion."

"There's no doubt that history shows us that nations that are strong militarily over time have to have a strong economy, as well. And that is one of the challenges that America faces," McCain said. "The challenge is to know when the United States of American can beneficially effect the outcome of a crisis, when to go in and when not, when American military power is worth the expenditure of our most precious treasure." (Watch Video: Economy Affect Military?)

Should the U.S. chase al-Qaida into Pakistan?

"I believe that part of the reason we have a difficult situation is because we made a bad judgment going into Iraq in the first place when we hadn't finished the job of hunting down bin Laden and crushing al-Qaida," Obama said, adding that bin Laden escaped and set up base camps in the mountains of Pakistan. "If we have Osama bin Laden in our sights and the Pakistani government is unable or unwilling to take him out, then I think that we have to act and we will take them out; we will crush Al Qaeda. That has to be our biggest national security priority."

"My hero is a guy named Teddy Roosevelt," McCain said. "Teddy Roosevelt used to say talk softly, but carry a big stick. Sen. Obama likes to talk loudly. In fact, he said he wants to announce that he's going to attack Pakistan. Remarkable. You know, if you are a country and you're trying to gain the support of another country, then you want to do everything you can that they would act in a cooperative fashion. When you announce that you're going to launch an attack into another country, it's pretty obvious that you have the effect that it had in Pakistan: It turns public opinion against us." (Watch Video: Pakistan Incursions?)

Can the U.S. work with Russia?

"We're not going to have another Cold War with Russia," McCain said. "But have no doubt that Russia's behavior is certainly outside the norms of behavior that we would expect for nations which are very wealthy, as Russia has become, because of their petro-dollars. ... We have to make the Russians understand that there are penalties for these this kind of behavior, this kind of naked aggression into Georgia, a tiny country and a tiny democracy."

"The resurgence of Russia is one of the central issues that we're going to have to deal with in the next presidency," Obama said. Pointing to the Georgia, the Ukraine, Poland, Estonia and Latvia, he said the U.S. must "provide them with financial and concrete assistance to help rebuild their economies. Georgia in particular is now on the brink of enormous economic challenges. And some say that that's what Putin intended in the first place." (Watch Video: Work With Russia?)

If Iran attacks Israel, does U.S. act alone?

"We cannot allow Iran to get a nuclear weapon. It would be a game-changer in the region. ... It's unacceptable. And I will do everything that's required to prevent it," Obama said. "We will never take military options off the table. And it is important that we don't provide veto power to the United Nations or anyone else in acting in our interests. It is important, though, for us to use all the tools at our disposal to prevent the scenario where we've got to make those kinds of choices."

"Let me say that we obviously would not wait for the United Nations Security Council," McCain said. "I think the realities are that both Russia and China would probably pose significant obstacles. And our challenge right now is the Iranians continue on the path to acquiring nuclear weapons, and it's a great threat. It's not just a threat -- threat to the state of Israel. It's a threat to the stability of the entire Middle East." (Watch Video: What If Iran Attacks Israel?)