Republican presidential hopefuls rubbed elbows with Iowans Saturday in a last-ditch effort to pick up support for the straw poll.

"Change begins in Iowa. It begins today. You're going to make it happen. Let's go out there and win one," former Mass. Gov. Mitt Romney told supporters, a 2008 hopeful picked by some observers to win the poll.

The Iowa Straw Poll is held on the same day as the Iowa State Fair but the events are not related. The state fair is a nonpartisan outing held by the state.

Huge air-conditioned tents dotted the grounds as the various campaigns sought to woo Republican voters with food and prizes. Activists from the National Rifle Association, anti-abortion groups and other organizations were also on hand.

About 40,000 people are expected to attend the poll — the Iowa Republican Party's biggest fundraiser expected to raise at least $1 million — which some see as bribery for votes.

Sen. Sam Brownback, R-Kansas, another GOP contender, labeled himself as a dark horse candidate.

"You're the key ground and I'd like to be one of those people moving forward. On our side of the aisle, I think it's set for a dark horse candidate to come through and I'd like to be that candidate," Brownback said.

One campaign paid for some Iowans' tickets for the poll, which costs $35 per person, with moon walks, pork chops on-a-stick and other activities.

Sen. John McCain, R-Ariz., former New York Mayor Rudy Giuliani and former Sen. Fred Thompson decided against competing in the poll.

Mike Huckabee, former governor of Arkansas, explained why he's in the poll.

"For them to make that trip and to come down here and cast a ballot, it does say something about a candidate's capacity to motivate and organize voters. That will be the base for what he does in the caucuses in January or December or November or next week, depending on when the caucuses get moved," Huckabee said.

Each voter marks a ballot at the straw poll that is fed into a voting machine. Results are expected Saturday night.

On Friday, a judge refused to issue an injunction that would halt the straw poll after a lawsuit questioned the constitutionality of the voting process at the event.

"In the absence of some legal violation, the Republican Party can run their (event) however they want," Judge James Gritzner said in his decision, which quickly followed the hearing because the straw poll was scheduled to start Saturday morning.

The lawsuit was filed late Thursday, and the judge said there wasn't adequate notice given to the defendants, who were served early Friday morning. The defendants included State Auditor David Vaudt, Story County Commissioner of Elections Mary Mosiman and Republican Party Chairman Ray Hoffmann. Representatives of the party attended the hearing, but the other defendants did not show.

FOX News' Steve Brown, Carl Cameron and The Associated Press contributed to this report.