Barack Obama and John McCain debate in Nashville

Cartoon campaign buttons for the two presidential candidates Photograph: Mike Blake /Reuters

George Bush and Sarah Palin impersonators give their support at Belmont University, Nashville, Tennessee, which was hosting the second debate Photograph: Jim Young/Reuters

The former Massachusetts governor Mitt Romney, left, chats to the former vice-president Al Gore, lower right, the former Tennessee senator Fred Thompson, top, and Gore's wife, Tipper, before the debate Photograph: J. Scott Applewhite/AP

The moderator, NBC's Tom Brokaw, takes the stage Photograph: Scott Olson/Getty

Barack Obama and John McCain wave to the audience Photograph: Charles Dharapak/Getty

Barack Obama answers the first question Photograph: Rick Wilking /Reuters

Obama makes a point as John McCain walks by Photograph: Alex Brandon/AP

Obama and McCain smile during an exchange Photograph: Carlos Barria/Reuters

The two candidates respond to a question Photograph: Jason Reed /Reuters

Obama looks on as McCain takes his turn to make a point to the crowd Photograph: Jim Young/Reuters

A wide shot of the venue at Belmont University Photograph: Jim Bourg/AP

John McCain salutes an audience member Photograph: Carlos Barria/Reuters

McCain and his wife, Cindy, join Obama and his wife, Michelle, in talking to the audience at the end Photograph: Charles Dharapak/AP