An image from a superPAC ad attacking Newt Gingrich, whose campaign called on TV stations to pull the ad off the air. Restore Our Future hide caption

itoggle caption Restore Our Future

Rick Santorum and Mitt Romney took the stage in a January presidential debate in Florida. They'll meet again Wednesday night in Arizona, which holds its primary on Feb. 28, the same day as the crucial Michigan contest. Paul Sancya/AP hide caption

itoggle caption Paul Sancya/AP

Then a congressman from Georgia, Newt Gingrich laughs at a joke told by President Reagan in Atlanta in 1984. Joe Holloway Jr./AP hide caption

itoggle caption Joe Holloway Jr./AP

Republican presidential hopeful Newt Gingrich made campaign stops on Florida's Space Coast on Wednesday, saying space is part of America's destiny and outlining what he called a bold plan to send Americans to the moon and beyond. Here, the former House speaker delivers remarks outside a restaurant in Coral Springs, Fla. Paul J. Richards/AFP/Getty Images hide caption

itoggle caption Paul J. Richards/AFP/Getty Images