The primary race in Iowa continues (39 images)

Republican 2012 presidential candidate and former US House Speaker Newt Gingrich signs the back of the shirt worn by Luke Cavanaugh, 14, as his wife Callista watches at a meet-and-greet at Al-Jon Manufacturing, a manufacturer of heavy snow removal machinery and recycling machines, in Ottumwa, Iowa, December 20, 2011, in advance of Iowa's first-in-the-nation caucuses, January 3,2012. UPI/Mike Theiler

Republican 2012 presidential candidate and Texas Gov. Rick Perry makes remarks to customers and supporters during a campaign stop at the Copper Coffee Cup in Cherokee, Iowa, December 16, 2011, in advance of Iowa's first-in-the-nation caucuses, January 3, 2012. UPI/Mike Theiler

Supporters of Republican 2012 presidential candidate and Texas Rep. Ron Paul await the arrival of Paul for a town hall meeting in Washington, Iowa, December 21, 2011, in advance of Iowa's first-in-the-nation caucuses, January 3,2012. UPI/Mike Theiler

Republican 2012 presidential candidate and former US House Speaker Newt Gingrich and wife Callista wait to be introduced at a meet-and-greet at Al-Jon Manufacturing, a manufacturer of heavy snow removal machinery and recycling machines, in Ottumwa, Iowa, December 20, 2011, in advance of Iowa's first-in-the-nation caucuses, January 3,2012. UPI/Mike Theiler