(CNN) -- Rick Santorum awoke to a new reality Wednesday after sweeping all three Republican presidential contests a day earlier, reshaping the contest that will decide who runs against President Barack Obama in November. Santorum won caucuses in Minnesota and Colorado, as well as a nonbinding primary in Missouri to energize his campaign and raise questions about front-runner Mitt Romney's ability to attract broad conservative support. The victories by Santorum bolstered his contention that he is the strongest conservative challenger to the more moderate Romney for the GOP nomination, and the most formidable conservative candidate to take on Obama. "I don't stand here and claim to be the conservative alternative to Mitt Romney," Santorum declared to cheering supporters outside St. Louis. "I stand here to be the conservative alternative to Barack Obama."

He canceled stops in
Minnesota scheduled for Monday to concentrate on Colorado, where he spent caucus night.