Rick Santorums wife, Karen, looks on as he speaks at a primary night watch… (Jeff Roberson, AP )
Reporting from Washington — Republican long shot Rick Santorum poked holes in Mitt Romney's aura of inevitability Tuesday night with a trio of upset victories that shifted the dynamic of the 2012 presidential contest.
The former Pennsylvania senator's wins in the Minnesota and Colorado caucuses and Missouri primary were setbacks for Romney, the national front-runner, who had been expected to cruise easily through a series of relatively minor February voter tests. He must now wait three weeks to regroup, when Arizona and Michigan hold what suddenly are shaping up as unexpectedly important primaries.
In remarks to delirious supporters in St. Charles, Mo., Santorum took a swipe at Romney's big advantage in money and the negative ads he's used to defeat his opponents in previous states. He also lashed out at President Obama, describing him as someone "who thinks he knows better" and doesn't listen to the American people.
Interactive: GOP primary overview
"Ladies and gentlemen, I don't stand here to claim to be the conservative alternative to Mitt Romney. I stand here to be the conservative alternative to Barack Obama," Santorum said, setting off chants of "We pick Rick!"
Reflecting what he sees as the altered shape of the race, Santorum told CNN that "now we're in a little bit of a no-man's land" as the candidates move into states where they haven't had months, or years, to campaign.
Romney, who won Minnesota four years ago, was running a weak third behind Santorum and Ron Paul.
Speaking to a deflated crowd of backers in Denver, Romney said he was "pretty confident" he would come in either first or second in Colorado's caucuses, his last hope for salvaging a bad night. But hours later, state Republican Chairman Ryan Call announced over CNN that Santorum had won.
PHOTOS: Campaign 2012 highlights
He congratulated Santorum and said that he looked forward to coming contests and a united party when the primaries ended. But he also struck a pose as a populist outsider, speaking of his father's humble roots and casting himself as the antidote to the problems in the nation's capital.
"Washington will never be reformed by those who have been compromised by the culture of Washington," he said, noting that he had "never served a day" there. And in another shot at his three remaining rivals, he added that leadership is about starting a business, "not getting a bill out of committee."
But his parting line — "we've got a long way to go" — spoke to the changed circumstances of the GOP contest. Many analysts had said that the race was over, a conclusion not supported by the results late Tuesday.
Santorum's rise poses a serious threat to Newt Gingrich, who had hoped to emerge as the conservative alternative to Romney. The former House speaker fared poorly as Republicans cast ballots in three states, and he is in serious danger of slipping behind Santorum in the GOP race and the fight to be Romney's main foe.
Romney, still the favorite for the GOP nomination, had managed to put together back-to-back successes with wins in Florida and Nevada. Santorum, whose last victory came more than a month ago in Iowa's leadoff caucuses, had his best showing since that day.
Paul, the only candidate without a victory, has been targeting caucus states, including the two voting Tuesday. Delegates in both states will be apportioned later, and Missouri's primary has no connection to delegate selection.
"We're well on our way, and we're going to keep our momentum," the Texas congressman, who is hoping to win his first state when Maine announces the results of its caucuses on Saturday, told supporters late Tuesday in suburban Minneapolis.
In Colorado and Minnesota, voters were gathered at precinct caucuses, where straw polls were conducted to reflect attendees' presidential preferences.
Tuesday's caucuses were conducted under the same process as those in Iowa, which took weeks to sort out. Romney initially was said to be the winner, but after state party officials checked ballots, Santorum was declared the winner, defeating Romney by 34 votes out of more than 121,500 cast.
The Missouri primary provided Santorum with his clearest opportunity yet to go head-to-head with Romney as the conservative alternative, since Gingrich had failed to qualify for the statewide ballot. Gingrich and Santorum have competed to eliminate the other and become the ultimate choice of the party's most ardent conservatives against Romney.
But their cause — stopping the front-runner — is likely to have a better chance of succeeding if both Santorum and Gingrich remain viable candidates, at least for now.
Recent primary polling has indicated that if one of them were to drop out, at least a portion of his support would go to Romney, allowing the former Massachusetts governor to gain delegates more quickly than if the anti-Romney vote continued to be divided among several candidates.