Sen. Obama and Sen. McCain wave to the crowd at the start of the town hall-style debate Oct. 7

Presidential candidates Barack Obama and John McCain met for their second debate Tuesday night in Nashville, Tenn. NBC journalist Tom Brokaw moderated, attempting to hold candidates to strict time limits as had been agreed to prior to the debate. Questions came from the audience in a town hall-like format, as well as from the Internet and Brokaw.

Questions focused on the economy, taxes, the future of entitlement programs, health care, energy and the U.S.’s role in foreign affairs.

One question from the Internet asked, “What don’t you know, and how will you learn it?” Sen. Obama responded, “One of the things about the presidency is, it’s never the challenges you expect, it’s the challenges that you don’t.”

If you missed the debate, watch it online! And once you’ve watched, check out the truth of the candidates’ statements at sites like factcheck.org and politifact.com, and on their campaign web sites (Obama, McCain).

Media Credit: Philly.com / Mark Humphrey, AP