Former Massachusetts Gov. Mitt Romney addressed supporters at a Super Tuesday rally in Boston on Tuesday. His home state was one of the six he won Tuesday night. Jessica Rinaldi /Reuters /Landov hide caption

itoggle caption Jessica Rinaldi /Reuters /Landov

Ten states hold GOP nominating contests on March 6. Here a voter heads to a polling station Tuesday morning in Cambridge, Mass., where former Gov. Mitt Romney is expected to win his home state. Emmanuel Dunand /AFP/Getty Images hide caption

itoggle caption Emmanuel Dunand /AFP/Getty Images