Rick Santorum told voters in Mandeville, La. on Wednesday that they were "not looking for someone who's the Etch A Sketch candidate." Sean Gardner /Reuters /Landov hide caption

itoggle caption Sean Gardner /Reuters /Landov

Restore Our Future, the superPAC supporting Mitt Romney, is running negative ads about Newt Gingrich in Ohio ahead of Super Tuesday on March 6, 2012. Restore Our Future hide caption

itoggle caption Restore Our Future

A camera is used instead of a rearview mirror on the Toyota NS4 plug-in hybrid concept car at the North American International Auto Show in Detroit on Jan. 10. Mike Cassese/Reuters/Landov hide caption

itoggle caption Mike Cassese/Reuters/Landov

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

Volunteer fire fighter Joe Crawford fights a wildfire in Graford, Texas, in September, when wildfires swept through parts of Texas and Oklahoma. Tom Pennington/Getty Images hide caption

itoggle caption Tom Pennington/Getty Images

Newt Gingrich speaks Monday at Global Security Services in Davenport, Iowa. Despite falling poll numbers, Gingrich says he will avoid negative campaigning. Chris Carlson/Associated Press hide caption

itoggle caption Chris Carlson/Associated Press

Republican presidential candidate Ron Paul spoke at a town hall meeting at the Ericson Public Library in Boone, Iowa, on Thursday before a university rally. Kevork Djansezian/Getty Images hide caption

itoggle caption Kevork Djansezian/Getty Images

George Allen, a former U.S. senator and Virginia governor, speaks to employees of an auto parts manufacturing plant near Roanoke, Va., on Oct. 5. Allen is trying to recapture the Senate seat he lost in 2006. Stephanie Klein-Davis/AP hide caption

itoggle caption Stephanie Klein-Davis/AP

A Predator drone takes off on a U.S. Customs Border Protection mission from Fort Huachuca, Ariz. Ross D. Franklin/AP hide caption

itoggle caption Ross D. Franklin/AP

This video frame grab provided by the Mitt Romney presidential campaign shows a scene from an ad called "Believe in America" that is running in New Hampshire. Romney Presidential Campaign/AP hide caption

itoggle caption Romney Presidential Campaign/AP

In September 1994, then-House Minority Whip Newt Gingrich addressed Republican congressional candidates on Capitol Hill during a rally where they pledged a new "Contract with America." Months later, Republicans gained control of both houses of Congress for the first time in decades, and Gingrich became speaker of the House. John Duricka/AP hide caption

itoggle caption John Duricka/AP