In Colorado, a Struggle Between Pragmatism and Passion GOLDEN, Colo. - Enthusiasm for a candidate is often what swings a caucus, with its small number of voters. But in Colorado's Republican Party, the divide between traditional party pragmatists and the forces of passion - a local and potent brew of evangelical religion, antitax fervor and suspicion of anointed establishment front-runners - has become institutionalized. Rick Santorum caught that wave on Tuesday. He did well where the ideological corner of the party is strong - notably Colorado Springs/El Paso County and Grand Junction/Mesa County in the West. Mr. Romney did well in places where traditional Republicans hold sway - notably the suburbs of Denver. Turnout in the areas Mr. Santorum where did well held steady or was up slightly compared with turnout at the 2008 caucuses. In the bedrock areas of support for Mr. Romney that helped him win the 2008 caucus, by contrast, turnout declined. In the Denver suburbs, a Romney stronghold, turnout was down to 3,249 votes, versus 4,071 four years ago, blunting the edge for him. Bad weather in Denver? Lukewarm support for Mr. Romney? Some combination that made sitting by the fire or watching reruns of "Glee," more appealing? Conditions on the roads and in school parking lots were certainly treacherous, and slips on the ice were observed in many places. But there's also history: In 2010, the Republican Party's hand-picked nominee for the Senate, Jane Norton, was derailed, with a Tea Party favorite, Ken Buck, winning to the nomination. Mr. Buck was subsequently defeated by Senator Michael Bennet, a Democrat. In 2005, Gov. Bill Owens, a Republican, drew the wrath of the party's ideological core by supporting a state referendum creating a time-out for a Taxpayer's Bill of Rights, a state constitutional amendment that strictly controls taxation and spending. Grover Norquist, the anti-tax crusader, called Mr. Owens politically dead. "This guy stood in front of a train," Mr. Norquist said at the time. Mr. Owens, a co-chairman of the Romney campaign in Colorado, said Wednesday that divisions in the party were temporary. The opposition to President Obama, which runs high, will be enough to reunite the party here around a Romney ticket, he said. "There are those who vote with their heart and those who vote with their head," he said. "I'm a William F. Buckley conservative," Mr. Owens added. "He said, "I'm for the most conservative candidate who can be elected." " He said, "In the end, Romney will be our nominee." Other Republicans said they saw in Tuesday's results a kind of shot across the bow in a looming battle for unaffiliated voters, about 30 percent of the state's electorate. In 2008, the unaffiliated vote broke in Colorado for Mr. Obama, and some Republicans say winning them back will not be about playing it safe. One thing consultants have always told Republicans is that we have to move to the center to win elections. I don't think that's true anymore," said Representative David G. Balmer, a Republican state representative from the suburbs of Denver. I think the electorate in Colorado is anxious to see Republicans stand up for conservative principals. Mr. Balmer is running for a state Senate seat and made no endorsement in the caucuses. "If an unaffiliated voter wants moderate positions," he said, "we're probably not going to get that voter anyway, but there will be those who migrate because we are standing up for the right things." Religion, especially conservative Christianity, is probably the wildcard force. In El Paso County, that voice spoke loudly for Mr. Santorum, politicians and analysts said, but whether in skepticism or hostility to Mr. Romney's Mormon beliefs or in embrace of Mr. Santorum's Catholicism was less certain. "Probably if you ask an El Paso County citizen, what was the number one issue in their minds, they might say the economy, but I find it interesting that their lead discussion is more on faith and religion," said Bill Roy, the chief operating officer for the El Paso County Republican Party. Mr. Roy said he had only anecdotal evidence that religious beliefs had swayed caucus goers toward Mr. Santorum. "Someone would walk up to the desk and say, "Hey that Rick Santorum, he's Catholic, man of faith, I'm liking him, he's got good values," " Mr. Roy said. "Instead of saying, "Boy, his conservative statements on immigration, and job creation and the nation debt appeal to me." " John A. Straayer, a professor of political science at Colorado State University in Fort Collins, said he thought that in a way, Mr. Romney perhaps did himself in in Colorado with the attacks on Newt Gingrich in recent days elsewhere on the campaign trail. With Mr. Gingrich's appeal diminished, Professor Straayer said, many Republican caucusgoers looked around for another choice, perhaps at the last minute. "Where they are going to go?" he said. Among many evangelical voters, he said, Representative Ron Paul of Texas, with his libertarian views on social issues like drugs, was not a viable choice, however they felt about Mr. Romney and his faith. And many Tea Party activists have similarly opposed Mr. Romney, who they have said is too moderate or too closely linked to the Massachusetts health care plan that became the template for the federal health care overhaul. "What Santorum probably picked up was some portion of the Tea Party crowd and evangelical crowd that had been willing to swallow Gingrich," he said. Professor Straayer said the Colorado General Assembly was probably the best place to look for how the Republican Party has changed over time, but even in the four years since Mr. Romney won the Republican caucuses. "I sometimes characterize the party as a marriage between Grover Norquist and James Dobson," he said, referring to the founder and former head of the conservative Christian group, Focus on the Family, based in Colorado Springs. "You've got the kind of libertarian, antigovernment, antitax orientation," he said, "and then you've also got the religious element, heavy in El Paso County. But it's not just El Paso County, it's all over the state, and they not only merge in numbers, but they merge in individuals. Mr. Balmer, the state representative, said Tuesday's results were all about rooting for the underdog. "Colorado loves the underdog," he said. In 2008, that was Mr. Romney, in his fight against the eventual party nominee, Senator John McCain. But none of that will matter, he said, once the dust settles and a nominee is named to go up against Mr. Obama. Then forget the splits. "President Obama has been the great Republican Party unifier," he said.