AP Photo/Evan Vucci
Former House Speaker Newt Gingrich speaks at Rock Springs Baptist Church on Sunday, Feb. 26 in Milner, Ga.
The Arizona governor formally announces her support to the former Massachusetts governor in the GOP race.
Paul Sancya / AP
Republican presidential candidate and former Pennsylvania Sen. Rick Santorum greets an audience member Saturday after a Tea Party rally in St. Clair Shores, Mich.
Voters Head to Polls Tuesday in Michigan and Arizona and President Obama talks Auto Industry Bailout
Mark Murray and Domenico Montanaro look back at the Arizona GOP debate and a tight race in the Michigan primary.
Scott Olson / Getty Images
DETROIT, MI - FEBRUARY 24: Members of the Detroit Economic club gather to hear a speech by Republican presidential candidate, former Massachusetts Gov. Mitt Romney. (Photo by Scott Olson/Getty Images)
The former Pennsylvania senator discusses his former colleague and why he won't be supporting Rick Santorum for president.
Saul Loeb / AFP - Getty Images
President Barack Obama speaks at the University of Miami in Florida on Feb. 23, 2012.
Tim Pawlenty on why he's supporting Mitt Romney for president.
Does Romney need to win Michigan to stay in the race? Will Santorum's comments on taking one for the team over No Child Left Behind hurt him going forward?