On Thursday night in Jacksonville, Fla., Mitt Romney (right) went after Newt Gingrich from the start on topics such as immigration and colonizing the moon. Matt Rourke/AP hide caption

itoggle caption Matt Rourke/AP

Republican presidential candidate Newt Gingrich speaks Thursday during a Lakeside Inn Tea Party rally in Mount Dora, Fla. Joe Raedle/Getty Images hide caption

itoggle caption Joe Raedle/Getty Images

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

Mitt Romney, accompanied by Rep. Ileana Ros-Lehtinen, R-Fla. (third from right), campaigns Wednesday at a U.S.-Cuba Democracy Political Action Committee event at Miami-Dade College in Miami. Charles Dharapak/AP hide caption

itoggle caption Charles Dharapak/AP

Casino owner Sheldon Adelson and his wife, Miriam, at the Marina Bay Sands complex in Singapore in June. The Adelsons have donated $5 million each to the pro-Gingrich superPAC Winning Our Future. Roslan Rahman/AFP/Getty Images hide caption

itoggle caption Roslan Rahman/AFP/Getty Images

Republican presidential candidate Newt Gingrich and his wife Callista Gingrich (in red) greet people during an event at the The River Church in Tampa, Fla., earlier today (Jan. 23, 2011). Joe Raedle/Getty Images hide caption

itoggle caption Joe Raedle/Getty Images

Republican presidential candidate Newt Gingrich and his wife, Callista, celebrate after Gingrich was declared the winner of South Carolina's primary Saturday. Mark Wilson/Getty Images hide caption

itoggle caption Mark Wilson/Getty Images

GOP presidential hopeful Newt Gingrich addresses the South Carolina Chamber of Commerce on Tuesday in Columbia, S.C. The state holds its primary on Saturday. Paul J. Richards/AFP/Getty Images hide caption

itoggle caption Paul J. Richards/AFP/Getty Images

Republican presidential candidate former House Speaker Newt Gingrich, accompanied by his wife, Callista, meets with parishioners during an event Saturday at the Jones Memorial AME Zion Church. Matt Rourke/AP hide caption

itoggle caption Matt Rourke/AP