INDIANOLA, Iowa (Reuters) - Six Democratic White House contenders mixed grilled steak and raw politics on Sunday, courting Iowa voters with promises of change and pledges to end the Iraq war and reverse many of President George W. Bush’s policies.

Democratic Presidential candidates and U.S. Senator Barack Obama (D-IL) (L), Bill Richardson (C), Governor of New Mexico and U.S. Senator Hillary Clinton (D-NY) stand for the National Anthem during the 30th annual Harkin Steak Fry in Indianola, Iowa, September 16, 2007. REUTERS/Joshua Lott

At Iowa Sen. Tom Harkin’s 30th annual “steak fry,” the candidates sampled the cuisine and fired up a big crowd of Democratic activists in the state that holds the first nominating contest in less than four months.

“Iowa is going to decide who will be the next president, not the chattering classes in Washington D.C.,” said New Mexico Gov. Bill Richardson.

More than 12,000 people, a record for the event, gathered on a grassy field normally used as a launching pad for Indianola’s summertime hot air balloon races to cheer the White House candidates.

New York Sen. Hillary Clinton leads the Democratic pack in national polls, but in Iowa state polls she is in a three-way dogfight with Illinois Sen. Barack Obama and former North Carolina Sen. John Edwards, the party’s 2004 vice presidential nominee.

The candidates urged Iowans to turn out to the polls in the November 2008 election, when Democrats hope to recapture the White House and increase the party’s majorities in Congress.

“Some of you out here -- you’re just sick and tired of George Bush,” Obama said. “We need a fundamental change.”

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Delaware Sen. Joseph Biden, chairman of the Foreign Relations Committee, said Bush made it clear last week he had no intention of ending the Iraq war before he left office.

“One of us on this stage is going to have to end the war he started, and that is deadly serious,” Biden said.

Obama, Biden, Richardson, Clinton, Edwards and Sen. Chris Dodd of Connecticut appeared at the event. Ohio Rep. Dennis Kucinich and former Alaska Sen. Mike Gravel were not invited because they do not have active campaigns in Iowa.

The crowd was bigger than the 10,000 who gathered in the rain in 2003 to hear from the Democrats running for president and from former President Bill Clinton, who took the stage at the end.

Harkin, who endorsed former Vermont Gov. Howard Dean in 2004 only to see his campaign collapse in Iowa, has said he is unlikely to endorse a Democrat before Iowa votes in January.

Last year, about 3,000 people gathered to get an early glimpse of Obama, who had not declared for president but urged the crowd to send Democrats to Congress.

To enter the field, ticket-holders had to walk a gauntlet of mostly college-aged kids yelling, ringing bells, blowing whistles and beating drums for their favorite candidate. Dave Hammer, 46, of Urbandale, Iowa, said he was not ready to make a choice yet.

“It’s way too early,” Hammer said, saying he wanted to hear the candidates but his sole hope for the afternoon was “for some good steak.”

Julie Bulver, 50, of Pleasant Hill, Iowa, was staking out some ground about two hours before the candidates were to begin speaking, aiming for the best view of the outdoor stage.

“It’s history. I’m hoping that one of these people will be our future president,” she said. “That’s why we brought the kids.”