Rick Santorum seized a solid lead Tuesday night in Minnesota's Republican caucuses, bidding to extinguish front-runner Mitt Romney's modest campaign winning streak and launch a comeback of his own in the race for the party's presidential nomination.

Romney was running a distant third in returns from one quarter of the state's precincts, trailing both Santorum and Rep. Ron Paul of Texas in a state he had won in his 2008 run for the nomination.

Colorado Republicans held caucuses as well, and the 70 delegates at stake in the two states combined were the biggest one-day total so far in the GOP race to name an opponent for President Barack Obama.

Santorum triumphed in the third state on the ballot Tuesday, winning a little-contested Missouri primary that was worth bragging rights but no delegates.

Returns from 25 percent of Minnesota's precincts showed Santorum with 44 percent support, Paul with 27 percent and Romney — who won the state in his first try for the nomination four years ago — with 17 percent. Former House Speaker Newt Gingrich trailed with 11 percent.

The first few hundred votes counted in Colorado trended Santorum's way, as well, but his count there lagged well behind Minnesota's.

Romney prevailed in both Minnesota and Colorado in 2008, but the GOP has become more conservative in both states since then with the influence of Tea Party activists.

There were 37 Republican National Convention delegates at stake in Minnesota and 33 in Colorado.

Santorum, a former Pennsylvania senator, campaigned aggressively in all three states, seeking a breakthrough to revitalize a campaign that has struggled since his narrow first-place finish in the Iowa caucuses a month ago.

Paul has yet to win a primary or caucus. He arrived at a caucus site in Coon Rapids, Minn., Tuesday evening to shake hands with early arrivers and had to squeeze his way through a crowd of autograph seekers.

Romney began the day the leader in the delegate chase, with 101 of the 1,144 needed to capture the nomination at the Republican National Convention this summer in Tampa, Fla. Gingrich had 32, Santorum 17 and Paul nine.

Taken together, the number of delegates at stake Tuesday was the largest one-day total yet in the Republican race to pick a rival for Obama. Even so, the campaigning was a pale comparison to the Iowa caucuses or primaries last month in New Hampshire, South Carolina and Florida.

Television advertising was sparse; neither Colorado nor Minnesota hosted a candidates' debate, and there was relatively little campaigning by the contenders themselves until the past few days.