VP debate: Joe Biden, Paul Ryan at each other on everything

Romney's choice of Ryan as running mate over the summer cheered conservatives in the House, many of whom regard him as their leader on budget and economic issues. The seven-term lawmaker has authored a pair of deficit-reducing budgets in the past two years that call for spending cuts and changes in Medicare, blueprints that Republicans passed through the House and Obama and his allies in Congress frequently criticize. He also champions a no-tax increase approach to economic policy.

As a senator before becoming vice president, Biden was chairman of the Foreign Relations and Judiciary committees, and he has long experience in national security issues. More recently, he was Obama's point man in arduous, ultimately unsuccessful negotiations with Republicans on steps to cut the deficit.

Both Ryan and Biden held extensive rehearsals, with stand-ins for their opponents.

Biden turned to Rep. Chris Van Hollen, D-Md., who is well-versed in Ryan's policy views from his tenure as senior Democrat on the Budget Committee.

Ryan's foil in rehearsal was former Solicitor General Ted Olson, a skillful courtroom advocate.

Associated Press writers Philip Elliott in Kentucky, Ken Thomas in Florida and Kasie Hunt in North Carolina contributed. Espo reported from Washington.