ABC: This Week, 9 a.m.

Newt Gingrich, former GOP speaker of the House.

NBC: Meet the Press, 9 a.m.

Former Secretary of State Colin Powell.

Fox News Sunday, 9 a.m.

Sen. John McCain, R-Ariz.

CBS: Face the Nation,

10:30 a.m.

Virginia Democratic Gov. Tim Kaine; Rep. Debbie Wasserman Schultz, D-Fla.; Missouri Republican Gov. Matt Blunt; former Rep. Rob Portman, R-Ohio.

CNN: Late Edition, 11 a.m.

Sen. Claire McCaskill, D-Mo.; Rep. Roy Blunt, R-Mo., House minority whip; former New York Mayor Rudy Giuliani; Rep. Artur Davis, D-Ala.; Ed Lazear, chairman, White House Council on Economic Advisers.