The following are some of the key exchanges between Senator John McCain and Barack Obama, in their second debate:
McCain: [Fannie Mae and Freddie Mac are] the ones that, with the encouragement of Senator Obama and his cronies and his friends in Washington, that went out and made all these risky loans... Senator Obama was the second highest recipient of Fannie Mae and Freddie Mac money in history. In history.
Obama: Senator McCain's campaign chairman's firm was a lobbyist on behalf of Fannie Mae, not me.
READINESS TO LEAD
McCain: That question can only be answered by someone with the knowledge and experience and the judgment... In his short career, he [Mr Obama] does not understand our national security challenges. We don't have time for on-the-job training, my friends.
Obama: Senator McCain suggests that somehow, you know, I'm green behind the ears... Senator McCain, this is the guy who sang, 'Bomb, bomb, bomb Iran,' who called for the annihilation of North Korea... This is the person who, after we hadn't even finished Afghanistan, where he said: 'Next up, Baghdad.'
BASHING GEORGE W BUSH
McCain: It was an energy bill on the floor of the Senate loaded down with goodies, billions for the oil companies, and it was sponsored by Bush and Cheney.
Obama: When George Bush came into office, we had surpluses. And now we have half-a-trillion-dollar deficit annually. When George Bush came into office, our debt - national debt was around $5 trillion. It's now over $10 trillion.
McCain: Well, you know, nailing down Senator Obama's various tax proposals is like nailing Jell-O to the wall. There has been five or six of them and if you wait long enough, there will probably be another one.
Obama: When Senator McCain proposes a $300bn tax cut, a continuation not only of the Bush tax cuts, but an additional $200bn that he's going to give to big corporations, including big oil companies, $4bn worth, that's money out of the system.
McCain: We can work on nuclear power plants. Build a whole bunch of them, create millions of new jobs. We have to have all of the above, alternative fuels, wind, tide, solar, natural gas, clean coal technology.
Obama: Our goal should be, in 10 year's time, we are free of dependence on Middle Eastern oil. And we can do it. Now, when JFK said we're going to the Moon in 10 years, nobody was sure how to do it, but we understood that, if the American people make a decision to do something, it gets done.
Obama: 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.
McCain: If you're a small business person and you don't insure your employees [for healthcare], Senator Obama will fine you. Will fine you. That's remarkable. If you're a parent and you're struggling to get health insurance for your children, Senator Obama will fine you.
Obama: When Senator McCain was cheerleading the president to go into Iraq, he suggested it was going to be quick and easy, we'd be greeted as liberators. That was the wrong judgment, and it's been costly to us.
McCain: If we had done what Senator Obama wanted done in Iraq, and that was set a date for withdrawal... then we would have had a wider war... Senator Obama would have brought our troops home in defeat. I'll bring them home with victory and with honour.
Moderator: Do you think that Russia under Vladimir Putin is an evil empire?
Obama: I think they've engaged in an evil behaviour and I think that it is important that we understand they're not the old Soviet Union, but they still have nationalist impulses that I think are very dangerous.
Moderator: Senator McCain?
Obama: If we have Osama Bin Laden in our sights and the Pakistani government is unable or unwilling to take them out, then I think that we have to act and we will take them out. We will kill Bin Laden; we will crush al-Qaeda.
McCain: He said he wants to announce that he's going to attack Pakistan. Remarkable. We need to help the Pakistani government go into Waziristan... not threatening to attack them... talk softly, but carry a big stick.
McCain: What would you do if you were the Israelis and the president of a country [referring to Iran] says that they are determined to wipe you off the map, calls your country a stinking corpse?... We can never allow a second Holocaust to take place.
Obama: We cannot allow Iran to get a nuclear weapon. It would be a game-changer in the region. Not only would it threaten Israel, our strongest ally in the region and one of our strongest allies in the world, but it would also create a possibility of nuclear weapons falling into the hands of terrorists.