A resurgent Rick Santorum won Minnesota's Republican caucuses with ease Tuesday night, relegating front-runner Mitt Romney to a distant third-place finish that raised fresh questions about his ability to attract ardent conservatives at the core of the GOP political base.

Santorum was victorious, as well, in a nonbinding Missouri primary that was worth bragging rights but no delegates.

A jubilant Santorum declared to cheering supporters in St. Joseph, Mo.: "Conservatism is alive and well in Missouri and Minnesota!"

Colorado held caucuses, too. The first few hundred votes tallied trended Santorum's way, but the count lagged well behind Minnesota's.

Returns from 42 percent of Minnesota's precincts showed Santorum with 46 percent support, Paul with 27 percent and Romney _ who won the state in his first try for the nomination four years ago _ with 16 percent. Former House Speaker Newt Gingrich trailed with 11 percent.

Romney prevailed in both Minnesota and Colorado in 2008, the first time he ran for the nomination, but the GOP has become more conservative in both states since then under the influence of tea party activists.

There were 37 Republican National Convention delegates at stake in Minnesota and 33 more in Colorado, and together, they accounted for the largest one-day combined total so far in the race for the GOP nomination.

Minnesota's victory was the first for Santorum since he eked out a 34-vote win in the lead-off Iowa caucuses a month ago.

He had faded far from the lead in the primaries and caucuses since, and Gingrich seemed to eclipse him as the leading conservative rival to Romney when he won the South Carolina primary late last month.