Santorum scores triple win  —  Rick Santorum dealt an embarrassing setback to Mitt Romney's presidential campaign Tuesday night, sweeping non-binding contests across three states and raising new questions about conservatives' willingness to accept Romney as their nominee.

Santorum Upsets G.O.P. Race With Three Victories  —  His candidacy all but dismissed just days ago, Rick Santorum won the Minnesota and Colorado caucuses and a nonbinding primary in Missouri on Tuesday, an unexpected trifecta that raised fresh questions about Mitt Romney's ability to corral conservative support.

The High Stakes in Minnesota, Colorado and Missouri  —  A cynic might say that tonight's Republican contests in Minnesota, Colorado and Missouri deserve an asterisk.  In Minnesota and Colorado, which will hold caucuses, voters will pick their preferred presidential candidate in a nonbinding straw poll …

Romney's lead dips despite wins: Reuters/Ipsos poll  —  (Reuters) - Despite his strong showing in early state contests in the race for the Republican presidential nomination, Mitt Romney's support nationwide has dipped slightly during the past month, according to a new Reuters/Ipsos poll released on Tuesday.

Rick Santorum wins Colorado Republican caucuses  —  Former U.S. Sen. Rick Santorum upended the race for the Republican nomination Tuesday, winning three states, including Colorado.  —  Colorado's race see-sawed throughout the night until 11 p.m., when Colorado GOP chairman Ryan Call declared Santorum …

Santorum shakes up GOP race with three-for-three finish  —  The Republican presidential contest is a two-man race no more.  —  Rick Santorum proved that the 2012 primary election still has a few surprises left, after he went three for three in Tuesday's contests and once again shook up the GOP nomination battle.