ANDOVER, Minn. — Minnesota Republicans headed to caucus meetings Tuesday determined to back a candidate who could defeat President Barack Obama in November, handing Rick Santorum a clear victory and at least temporarily shaking up the race for the GOP nomination.

“I want to see Obama replaced,” said Bruce Olson, a retired state employee who attended a caucus meeting in Andover, a suburb northwest of Minneapolis. “How we get there remains to be worked out.”

Santorum emerged as the clear winner early in the evening, comfortably ahead of second-place Ron Paul, with a victory that rewarded a series if visits to Minnesota in the final week. Front-runner Mitt Romney was well back in third, with Newt Gingrich last.

With 100 percent of precincts reporting in Mower County, Santorum claimed 143 votes out of a possible 278. Second place went to Ron Paul with 79 votes, followed by Romney with 32, and Gingrich with 21.

Santorum also won Freeborn County.

Bruce Mackenthun, a 38-year-old contractor at a caucus in Shakopee, called Santorum a “consistent conservative” without some of Romney’s negatives and with a better foreign policy than Paul.

“He seems to have a clear message,” Mackenthun said. “He hasn’t had to change it really through the whole campaign.”

The night’s preference ballot doesn’t bind any of the 40 national convention delegates, but it offers plenty of symbolic importance. Coming off back-to-back primary wins in Nevada and Florida, Romney had hoped contests in Minnesota, Missouri and Colorado would distance him from the GOP pack.

Romney won the Minnesota caucus in 2008 running as the conservative alternative to John McCain, but this year saw other candidates run to his right. Olson, who said he was open to Santorum or Gingrich, said he had concerns about Romney. “I like Romney OK but I think he’s a little liberal.”

Ernie Bedor, a 59-year-old insurance agent, spoke in support of Romney during his precinct caucus meeting. “I think Romney, with his business background, would be a better choice to stimulate our economy, get this economy going and create more jobs.”

Nancy and Tom Hill both voted for Paul. Nancy Hill, an assistant to a financial planner, said she’s “evolved over the years from Democrat to independent to Republican.” But she said she’s supporting Paul because she sees him as the only Republican willing to truly rein in federal spending.

In addition to talking about presidential choices, caucus-goers in Andover touched briefly on issues including several planned or proposed constitutional amendments. They heard a pitch from supporters of the amendment to define marriage in the state Constitution as between a man and a woman only. That prompted debate in the second precinct meeting, with several speaking out for the traditional definition of marriage but a few others opposed or at least undecided.

Cindy Showalter, a nurse, said she had spoken to her 21-year-old son about the issue. “He asked me, ‘Would you want the government telling you and dad you couldn’t get married?'” she said.

In 2008, more than 60,000 Republicans attended a caucus — helping Romney easily defeat McCain. Party insiders said despite the competitive nature of the 2012 caucuses, they weren’t expecting to rival that number. In Andover, site coordinator Janna Goodrich said the caucus appeared to her to have drawn about three-fourths the number of people that attended in 2008. At one Rosedale hub for several precincts, GOP officials estimated attendance was down from about 350 four years ago to about 300 this time around.

By contrast, in Shakopee — a suburb south of Minneapolis — a line of about 50 people steadily ambled through the Shakopee High School lobby. An organizer, Deputy Chairman of Scott County Republicans Ryan Love, said attendance at his precinct jumped from 5 people four years ago to almost 20 this year.

Jannette Costa, 40, a stay-at-home mother of two daughters, said fiscal and social issues brought her to the Shakopee gathering. She said she’s not that happy with either party but supports Santorum: “He’s pro-life. He seems to have a very good understanding of the Constitution and the Declaration of Independence and of what the founders intended for our country.”

Leon King, 64, said he was supporting Gingrich with the thought he’d be the best match for Obama in presidential debates. “He’s more experienced,” King said.

Santorum and Paul, both trying to boost their underdog status, made last-minute appeals to Minnesotans on caucus day. Speaking to more than 100 supporters in the suburb of Blaine, Santorum blasted Romney as a candidate with too many problems in his record to provide a contrast with Obama.

“Minnesota, you don’t need to settle for second best. Pick the best,” said Santorum, a former Pennsylvania senator.

Paul worked the state hard, dropping in on two caucuses before heading to his own election night party outside Minneapolis. Since Saturday, Paul has drawn thousands to several events, particularly young voters.

Showalter, the nurse at the Andover caucus, said she decided to attend after a discussion with her 21-year-old son, a Paul supporter. Showalter said he’s “pumped up” about the election.

“It was embarrassing to hear him say that he was going to caucus and we’d never been to one,” Showalter said. “So we decided to go.”