A resurgent Rick Santorum swept primaries in Alabama and Mississippi Tuesday night, upending the race for the Republican presidential nomination as he sought to push Newt Gingrich toward the sidelines.

Mitt Romney accepts an endorsement from Arizona Sen. John McCain, the 2008 Republican presidential nominee, as the former Massachusetts governor pushes for a victory in next week's New Hampshire primary.

U.S. Republican presidential candidates were criss-crossing the state of New Hampshire in the final day of campaigning ahead of a Tuesday primary contest that could cement Mitt Romney's status as the inevitable challenger to incumbent Barack Obama.

Floridians prepare to vote in Tuesday's Republican presidential primary amid increased uncertainty over the state's hard-hit housing market — an issue that has prompted plenty of campaign barbs and a dearth of proposed solutions.