Minnesota Republican Rep. Michele Bachmann and her husband, Marcus, recite the Pledge of Allegiance before announcing her candidacy for president last June in Waterloo, Iowa. Steve Pope/Getty Images hide caption

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Courting Tea Party voters in Philadelphia on Monday night, Mitt Romney speaks next to a large statue of Benjamin Franklin at the Franklin Institute. Tim Shaffer/Reuters/Landov hide caption

itoggle caption Tim Shaffer/Reuters/Landov

Standard & Poor's downgrade of the U.S. credit rating Friday will play a role in President Obama's political future. Carolyn Kaster/AP hide caption

itoggle caption Carolyn Kaster/AP