Rick Santorum is back. After four straight losses to Mitt Romney, the former Pennsylvania senator won at least three states -- Oklahoma, North Dakota and Tennessee -- on Super Tuesday. He was aggressively challenging Romney in the night's marquee race in Ohio.
Even before all the states were decided, it was clear that Santorum's position as Romney's chief Republican opponent was still intact.
"This was a big night tonight," Santorum told cheering supporters at a Steubenville, Ohio, high school. "We have won in the West, the Midwest and the South, and we're ready to win across this country."
The victories, which come as 10 states held elections from Alaska to Vermont, gave the Santorum campaign a badly needed shot of momentum. Romney was coming off a four-state win streak and had won Tuesday in Massachusetts, Vermont and Virginia, with a handful of races too close to call.
Newt Gingrich won his home state of Georgia.
Santorum's victories in two southern states seemed to be enough to fuel his underdog campaign, despite increasingly calls for the candidates to rally around front-runner Romney. But a victory in Ohio could reshuffle the Republican contest, sending a powerful message that Romney's grasp on his party's nomination is by no means assured.