Updated

Rick Santorum was mining suburban St. Louis for last minute support Saturday, as Missouri Republicans began gathering in local caucuses that will help determine who gets the state's 52 presidential delegates that are up for grabs.

Santorum won the state's nonbinding primary last month and was the only one of the four Republican presidential candidates visiting caucus sites Saturday. Former Massachusetts Gov. Mitt Romney and Texas Rep. Ron Paul also campaigned in Missouri earlier in the week. Former House Speaker Newt Gingrich skipped the state.

No winner will be declared from the nearly 140 local caucus meetings Saturday. That's because the state party rules do not require local delegates to be bound to any candidate, and no straw poll is being conducted. Saturday's meetings will elect 2,123 people to advance to congressional district conventions on April 21 and a state convention on June 2. It's at those meetings that most of Missouri's 52 delegates will be bound to presidential candidates.

Santorum, Romney and Paul were nonetheless urging supporters to attend the local caucuses, hoping to advance a slate of backers to the district conventions.

The former Pennsylvania senator started Saturday at a rally of about 100 people in a Christian school gymnasium, where he spoke less than four minutes, shook hands for 10 more, then headed out to the next caucus site, a supermarket in a wealthy St. Louis suburb. He arrived about an hour early and spoke ahead of schedule to the 150 people present. Those who showed up closer to his scheduled time were told he had already gone.

Steve Mosbacher, a 53-year-old business owner from St. Louis County, was among the early birds who caught Santorum's speech. Mosbacher said he likes Santorum but wonders if he can win.

"I worry because he lost his Senate bid," said Mosbacher, who said he is backing Ron Paul.

Acknowledging there would be no winner Saturday, Santorum told a reporter that Missouri's caucuses still were important.

"Delegates. It's as simple as that. They matter," Santorum said.

Romney leads Santorum in delegates nationwide 492 to 257, according to the latest count by The Associated Press. In his caucus-site speech, Santorum noted he was being outspent by Romney but said he can overcome that.

"We don't have the money," Santorum said at the Wildwood grocery store. "We have you, and I'll tell you what -- I'll take you over the money any day of the week."

At Westminster Christian Academy, Santorum was greeted by supporters as well as dozens of people with Romney signs planning to challenge local Republican leaders trying to elect a slate of Santorum delegates.

"I don't believe Santorum has enough real-life experience with business," said Carrie Jardine, 45, a chiropractor from Chesterfield, one of the Romney supporters who shook Santorum's hand. "I believe Romney is a proven hard-hitter -- he knows what to do and he knows when to do it."

Norman Baxter, 77, a retired corporate communications officer who is the Republican committeeman for the local township, is pushing the Santorum slate.

"I'm a conservative -- a strong conservative -- and I think Santorum represents a lot of the values that I think are very, very important to the survival of this country," Baxter said.