Republican presidential candidate, former U.S. Sen. Rick Santorum speaks at a campaign rally at Four Seasons Sheraton in Mars, Pa., Monday night. Rival Mitt Romney won the Washington, D.C., Maryland and Wisconsin primaries.
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After his losses in Alabama and Mississippi on Tuesday, Newt Gingrich will face increasing pressure to drop out of the GOP race. Here he waves to supporters after speaking at a rally in Hoover, Ala., on Tuesday.
Marvin Gentry /Reuters /Landov
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
Jan White, left, Brenda Robertson, center, and Janet Freixas, right, count paper ballots at the headquarters of the Douglas County Republican Party Saturday in Minden, Nev., following county-wide Nevada caucus meetings.
Ted S. Warren/AP