Gerald Herbert / AP
Republican presidential candidate, former Massachusetts Gov. Mitt Romney speaks to the traveling press corps after arriving in Atlanta, Wednesday, Feb. 8, 2012.
Rick Santorum is trying to capitalize on the momentum from his clean sweep in Tuesday's Republican presidential contests. NBC's Kelly O'Donnell reports.
Emmanuel Dunand / AFP - Getty Images
Republican presidential hopeful Mitt Romney holds a campaign rally at RV America in Loveland, Colorado, February 7, 2012.
NBC's Chuck Todd tells TODAY's Ann Curry that Rick Santorum's sweep of Tuesday's GOP presidential contests was a "rejection by conservatives of Mitt Romney."