U.S. Sen. Sherrod Brown (right), D-Ohio, debates his Republican challenger, Ohio state Treasurer Josh Mandel, at the City Club in Cleveland on Oct. 15. Tony Dejak/AP hide caption

itoggle caption Tony Dejak/AP

Republican presidential candidate Mitt Romney makes his case about Medicare during a briefing in South Carolina in August. Evan Vucci/AP hide caption

itoggle caption Evan Vucci/AP

President Obama is greeted by New Jersey Gov. Chris Christie upon arriving in Atlantic City, N.J., on Wednesday to visit areas hardest hit by Superstorm Sandy. Jewel Samad/AFP/Getty Images hide caption

itoggle caption Jewel Samad/AFP/Getty Images

A life-sized cardboard cutout of actor, director and politician Clint Eastwood stands next to an empty chair cutout north of Los Angeles, California. Eastwood's 12-minute conversation with an empty chair representing President Obama sparked much attention at the 2012 Republican National Convention. David McNew/Getty Images hide caption

itoggle caption David McNew/Getty Images

The presidency has remained a male-only office throughout American history. Despite changing demographics and huge gains by women in other walks of life, some experts still don't see a female president on the horizon. Joshua Roberts/Getty Images hide caption

itoggle caption Joshua Roberts/Getty Images