BOISE - Former Massachusetts Gov. Mitt Romney on Tuesday won Idaho's first-ever Republican caucus, capturing all 32 delegates after besting rivals Ron Paul, Rick Santorum and Newt Gingrich.

Romney coasted to victory in Idaho's largest county, Ada, as well as southern and eastern counties, including Bannock, Franklin, Power, Jerome, Twin Falls and Lemhi.

Organizers estimated 68,000 turned out statewide for Idaho's first-ever GOP caucus, including 9,000 people in Ada County and some 4,500 each in neighboring Canyon County and eastern Idaho's Bonneville County.

The crush was so great in Ada, an extra 30 minutes were allowed so hundreds of people still outside at the 7 p.m. cutoff could get into the Taco Bell Arena at Boise State University.

One of those, Rachel Fuller from Meridian, braved the cold, blustery weather with her 14-year-old son, Brennan, to support Romney - and to participate in something she and thousands of other Idaho Republicans had never done before.

"It's just exciting to be here, to be able to vote," Fuller said. "I'm excited to be here with all of these like-minded people."

The Ada County caucus began with short speeches from supporters of all four GOP contenders. Gov. Butch Otter rallied supporters to back Mitt Romney as the best person to challenge Democratic President Barack Obama in November.

Meanwhile, a cover band played John Mellencamp's song "Pink Houses," while former U.S. Sen. Larry Craig delivered a duet rendition of the "Star Spangled Banner" with a young high school accompanist.

Voting booths were shrouded in white curtains to protect privacy, as one Republican after another dropped shiny, 2011-minted Lincoln pennies with a light "plink" into buckets marked with each of the candidates' names.

When voters emerged from the booths, a volunteer shouted "Next."

Before Tuesday, Ada County Republican Chairman Dwight Johnson said a circle of "five or fewer" people knew pennies were to be used as voting tokens, to cut down on the potential for caucus fraud.

"There is no margin of error," Johnson said of counting machines on loan from a local bank to tally the coins.

Boise resident Francoise Teal came to support Rick Santorum, the former Pennsylvania senator who has gained momentum in recent weeks and made several stops in Idaho last month.

"This is a guy I'm really hoping and praying for," said Teal, an Italian by birth who became a U.S. citizen in 1958.

Her daughter, Jeanette Teal, also supported Santorum, but said she'd vote for Romney in November, if reluctantly.

"I'll vote for whoever I have to, to get Obama out of office," she said.

Some Paul supporters said the same thing: The main thing is to get a Republican back in the White House.

"I'm more anti-Obama than I am for Romney or Santorum," said Judith Waskow, of Boise. "I'm supporting any Republican who is going to defeat Obama."

In the past three weeks, Romney, Newt Gingrich, Ron Paul joined Santorum in making campaign stops in Idaho. Idaho Secretary of State Ben Ysursa gave the event a cautious nod of approval, saying he'd have a final verdict once the dust from the events statewide had settled.

"Participation is the key," said Ysursa, Idaho's top election official, while sitting in courtside seats at the BSU arena. "The other part of it, holding the caucus got all the presidential candidates here."

In the other nine states involved in Super Tuesday contests, Romney claimed victories in Vermont, Massachusetts and Virginia and was locked in tight race with Santorum in Ohio. Gingrich won in Georgia, while Santorum was declared the victor in Oklahoma, North Dakota and Tennessee.