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 was running third in both states.

"We did it again," Santorum told cheering supporters in Lafayette, La. He said it was time for conservatives to unite in an effort to defeat Romney, the former Massachusetts governor who is the faraway leader in the competition for Republican National Convention delegates.