Presidential hopefuls Rep. Michele Bachmann (R-MN), who signed a pledge against abortion rights, and businessman Herman Cain, who has not, seen at the taping of a radio show in New Hampshire in May. Jim Cole/AP hide caption

itoggle caption Jim Cole/AP

(March 29, 2011 file photo from Chicago): Controversial anti-abortion billboards depicting President Obama. They were sponsored by ThatsAbortion.com. Scott Olson/Getty Images hide caption

itoggle caption Scott Olson/Getty Images