Republican presidential candidate and former House Speaker Newt Gingrich speaks at the CBS News/National Journal foreign policy debate at the Benjamin Johnson Arena Spartanburg, S.C., on Nov. 12. Republican presidential hopefuls sharply criticized President Barack Obama's efforts to thwart Iran's nuclear ambitions as too weak, but disagreed about whether the United States would be justified in a pre-emptive military strike. Richard Shiro/AP/File
Newt Gingrich greets a supporter at a kickoff party for the opening of the Newt2012 office in Manchester, N.H., on Nov. 11. Winslow Townson/AP/File
Newt Gingrich and his wife Callista hold an oversize replica of an ax after signing a pledge to cut taxes, spending, and government in Concord, N.H., on Oct. 25. Jim Cole/AP/File
With his wife Callista at his side, Newt Gingrich fills out his papers at the New Hampshire Secretary of State's office to have his name on the nation's earliest presidential primary ballot in Concord, N.H., on Oct. 25. Jim Cole/AP/File
Speaker of the House Newt Gingrich (c.) discusses the gravity of the process of impeaching President Bill Clinton while flanked by (from l.) Rep. John Conyers, the ranking Democrat on the House Judiciary Committee, Minority Leader Richard Gephardt, Majority Leader Dick Armey, and Rep. Henry Hyde, chairman of the Judiciary Committee, during a press conference on Sept. 9, 1998. Andy Nelson/Staff/File
President Clinton smiles after signing the balanced budget bill on the South Lawn of the White House in Washington on Aug. 5, 1997. From left are Rep. Tom Davis III (R) of Virginia, Rep. Sheila Jackson Lee (D) of Texas, Vice President Al Gore, Sen. Frank Lautenberg (D) of New Jersey, Rep. Charles Rangel (D) of New York, House Speaker Newt Gingrich (R) of Georgia, Rep. Steny Hoyer (D) of Maryland, and House Budget Committee Chairman Rep. John Kasich (R) of Ohio. Ron Edmonds/AP/File
House Speaker Newt Gingrich blows out candles on his birthday cake as his daughter Jackie watches at Zoo Atlanta during a celebration for Gingrich's birthday on June 14, 1997. Gingrich shared his birthday celebration with Zoo Atlanta's famous gorilla, Willie B.
Vice President Gore and House Speaker Newt Gingrich talk behind President Clinton prior to his giving his State of the Union address on Capitol Hill in Washington on Jan. 23, 1996. Doug Mills/AP/File
House Speaker Newt Gingrich inspects the Tyrannosaurus Rex fossil, which the Smithsonian Institute lent to him for his office, in Washington on May 8, 1995. Gingrich, who had originally come under criticism for accepting the piece, is a noted historian and dinosaur aficionado. The fossil is from the Cretaceous period and was discovered in Montana. At rear is Smithsonian Secretary I. Michael Heyman. Reuters/File
House speaker Newt Gingrich tries to get ahold of an Asian bearcat (binturong) as it gnaws on his fingers during a visit from members of the Columbus, Ohio Zoo on Capitol Hill in Washington on April 5, 1995. Reuters/File
The late comic actor Chris Farley (r.) impersonates Speaker of the House Newt Gingrich before a regular meeting of House Republicans, as Gingrich (l.) applauds him in Washington on April 4, 1995.
Incoming Speaker of the House Newt Gingrich sits with his second wife Marianne at a church service prior to the opening of the 104th Congress in Washington on January 4, 1995. Reuters/File
Then-House Minority Whip Newt Gingrich of Georgia addresses Republican Congressional candidates on Capitol Hill in Washington on Sept. 27, 1994, during a rally where they pledged a 'Contract with America.' John Duricka/AP/File