Rick Santorum Wins Colorado, Missouri and Minnesota

(Reuters) - Former US senator Rick Santorum narrowly has won the Colorado Republican US presidential caucuses over Mitt Romney.

The victory gave Santorum a sweep of all three Republican presidential nominating contests on Tuesday, having already won in Missouri and Minnesota.

Rick Santorum defeated frontrunner Mitt Romney in the non-binding Republican presidential primary in Missouri, one of three states holding presidential nominating contests on the same day.

Santorum had about 55 percent of the vote while Romney - who has won three of the first five nominating contests - was in second with 25 percent, with 45 percent of the vote counted, according to the Missouri secretary of state's website.

Networks projected Santorum as the winner.

Missouri is one of three states holding Republican presidential nominating contests on Tuesday, with Minnesota and Colorado also holding caucuses in the state-by-state battle for the Republican nomination to face President Barack Obama in the November 6 election.

Santorum, aiming to reinvigorate his quest for the Republican nomination, also led in Minnesota in early returns.

It marked the second victory for Santorum, the former senator from Pennsylvania who narrowly beat Romney to win Iowa's caucuses on January 3.

The victory gives new hope to Santorum, a staunch social and religious conservative, and new momentum in his battle with former U.S. House of Representatives speaker Newt Gingrich to be viewed as the top conservative alternative to the more moderate Romney.

Gingrich was not on the ballot in Missouri, allowing Santorum the chance to consolidate conservative voters in the state and compete directly with Romney, the former Massachusetts governor, and U.S. congressman Ron Paul, known for his libertarian views.

Santorum spent the last two days campaigning in Missouri while Romney focused on Colorado, where he is favored.

The Missouri primary is considered a beauty contest because the candidates do not win delegates who will take part in the August Republican convention where the party's presidential nominee will officially be chosen. Missouri Republicans will select convention delegates in caucuses on March 17 in the state's two-step process.

But the primary still was considered a noteworthy test of strength among the candidates in a big Midwestern state.

Romney had won in New Hampshire, Florida and in the most recent contest in Nevada to seize control of the volatile Republican race.

Santorum has made his strong positions on social issues a centerpiece of his bid and is hoping his staunch opposition to gay marriage and abortion will help win over conservatives wary of Romney because of moderate positions he took while running for office in liberal Massachusetts.

Gingrich hopes his campaign can last until Super Tuesday contests in 10 states on March 6 and several later contests in March, when votes will be taken in southern states where he expects to do well.

Gingrich spent Tuesday campaigning in Ohio, one of the Super Tuesday states. Early voting begins in Ohio on Tuesday.

I think the big story coming out tonight is going to be that it's very hard for the elite media to portray Governor Romney as the inevitable nominee after tonight's over, Gingrich said on CNN.

A Reuters/Ipsos poll that has Romney ahead in the race nationally with 29 percent showed Santorum's support has gained by 5 percentage points in the last month, to 18 percent. That put him in a virtual tie with Gingrich, at 19 percent, and Paul, who was at 21 percent.