WASHINGTON – Rick Santorum seized a win Tuesday night in Minnesota’s Republican caucuses over rival Mitt Romney as he worked to launch a comeback in the race for his party’s presidential nomination.

With 36 percent of the precincts reporting, Santorum has 46 percent to Ron Paul’s 26 percent and Romney’s 16 percent. Former House Speaker Newt Gingrich was coming in last with about 11 percent.

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 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.

They will be chosen beginning in caucuses expected to draw far more competition from Romney, Gingrich and Paul next month.

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

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.

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.

He largely bypassed last week’s contests in Florida and Nevada to lay the groundwork for Tuesday’s trio of states. He’s been aggressively criticizing Romney and Gingrich and holding himself out as the candidate best able to defeat Obama.

Paul, a Texas congressman, has yet to win a primary or caucus.

He arrived at a caucus site in Coon Rapids, Minn., in early 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.

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.

The same was true in last weekend’s Nevada caucuses, which Romney won on the heels of a Florida primary victory days earlier.

The same pattern holds in Maine, where caucuses finish on Saturday.

Not until primaries in Michigan and Arizona on Feb. 28 is the campaign likely to regain the intensity that characterized the first few weeks of the year.

Then it roars back to life with a 10-state Super Tuesday on March 6 with 416 convention delegates at stake. Georgia, where Gingrich launched his career in Congress, is the biggest prize that night with 76 delegates. Next is Ohio, which has 63 delegates at stake.

Santorum, in particular, hoped to seize the relative lull to redeem the promise of his Iowa victory.

He campaigned more aggressively this week, and he spent the day hopscotching from Colorado to Minnesota to Missouri in hopes of nailing down a victory in one of the states. Touting himself as a true conservative – a slap at Gingrich – he sought to undermine Romney’s electability claim at the same time by predicting the former Massachusetts governor would lose to Obama.