WASHINGTON (Bloomberg Politics) - The Iowa State Fair has had locomotive collisions, a boar weighing 1,335 pounds and Johnny Cash for two performances that attracted 25,000.

Then on Saturday, Mr Donald Trump arrived. The billionaire Republican presidential candidate and his helicopter were hard to miss, even on a day when four other White House hopefuls also visited the fairgrounds.

The former reality television star overshadowed Mrs Hillary Clinton, Mr Bernie Sanders, Mr Rick Santorum and Mr Lincoln Chafee.

Iowans, who will host the first presidential nomination contest on Feb. 1, said they can't recall a time when so much political star power arrived at the fair on a single day.

To at least one candidate, there was no question who the biggest star of the day was.

"She had a crowd one-tenth of what I have," Mr Trump bragged to reporters, in a reference to Mrs Clinton, as he made his way across the fairgrounds amid a sweaty, sprawling crowd that encircled him.

The size of the mob of media and fair-goers following Mr Trump was among the largest ever to track a presidential candidate on the grounds in recent history. In fairness to Mrs Clinton, her entourage was restricted a bit by security concerns.

"Stick to your guns, Trump, stick to your guns," one man yelled at the Republican front-runner. Similar shouts were continually directed at Mr Trump as he walked, periodically stopping to talk to reporters and pose for photos with fans.

Wearing cream-colored slacks, bright white shoes and a dark sport coat, Mr Trump looked like he was dressed more for a golf tournament than an afternoon at the fair amid 87-degree temperatures. His red baseball cap, emblazoned with his "Make America Great Again" slogan, helped make him visible even when engulfed by people.

Along with other local officers and Mr Trump's own security detail, Major Randy Kunert, a large and good-natured Iowa State Patrol officer, he tried to enforce a sort of roving crowd control.

"If I touch you, you are too small for the rides," the 1.9m-tall Maj Kunert jokingly yelled, as his long arms sprawled out in a spread-eagle fashion to direct people to clear a path for the entourage.

Mr Trump offered relatively few handshakes or hugs. He didn't make Iowa small talk with the locals as most politicians do, or answer policy questions, instead mostly reveling in the size of the crowd around him.

While his staff had said Mr Trump would visit the butter cow, the Iowa Fair's iconic sculpture, he bypassed the stop, leaving some waiting for him there disappointed.

Mrs Clinton spent roughly twice as much time as Mr Trump at the fairgrounds - about 95 minutes. She toured with a Hawkeye host, former senator Tom Harkin, who endorsed her earlier this week.

Briefly taking questions from the media, she again defending her use of a private e-mail account while at the State Department and deflecting a question about any mistakes she's made during her four-month-old campaign by saying: "I'm just having a good time."

On any other day of this year's fair or in any other year, the former first lady, former New York senator and former secretary of state, and her escort, an Iowa political icon, would've been the top attraction.

They were still a major draw, but the shadows of the curiously coiffed man Mrs Clinton referred to on Friday night as the Republican Party's "flamboyant frontrunner" seemed to one-up them.

As Mrs Clinton and Mr Harkin made their way through the fair's crowds, they encountered some people who were waiting for Mr Trump.

As Mrs Clinton walked through a row of food tents, Mr Trump's helicopter circled above, noticed by her staffers, journalists and fair-goers.

Mrs Clinton later told reporters that she hadn't noticed because she was too engaged with potential voters.

Surrounded by a phalanx of Secret Service agents and state troopers, Mrs Clinton and Mr Harkin, wearing a straw hat, posed for photos and chatted with fairgoers. Amid the grip and grins, there were some gripes.

As Mrs Clinton waded through a mass of onlookers, one shouted: "Are you worried about going to prison?"

As Mrs Clinton neared a tent offering pork chop-on-a-stick - an item both she and Mr Trump sampled - one fair-goer groaned: "Hillary, get out. We don't want a politician. We want a pork chop line!"

Pork chop in hand, Mrs Clinton posed for selfies with the workers who'd handed it to her before taking a bite. "I highly recommend it," she told reporters.

After a few more minutes of working her way through the crowd, Mrs Clinton and her entourage reached a black SUV. She climbed in, pork chop in hand.

Other presidential candidates on the fairgrounds Saturday included Mr Chafee, a Democrat who is a former Rhode Island governor, and Mr Santorum, a former senator from Pennsylvania who won Iowa's Republican caucuses in 2012.

Mr Trump arrived at the fairgrounds after Mrs Clinton. The real estate mogul landed his Trump-labeled helicopter in the parking lot of softball field about a mile south of the fair.

He told reporters he thinks Mrs Clinton has "big problems" in relation to the e-mails, but he kept most of his focus on his fellow Republican candidates.

Mr Trump said former Florida Governor Jeb Bush is a "puppet to his donors" and criticized him for saying a day earlier at the fair that Iraqis want to know the US has "skin in the game" when it comes to increasing American troop strength in order to stabilize the country.

"We've spent US$2 trillion, thousands of lives lost, wounded warriors, who I love, all over the place, and he said we have to prove that we have skin in the game," Mr Trump said. "I think it may be one of the dumbest statements I've ever heard."

Mr Trump said he planned to unveil his ideas for immigration policy on Sunday and will issue a paper on tax policy in about two weeks. But Mr Trump added that it's mostly the media that cares about policy. Pressed later on the fairgrounds about that, he told reporters: "The voters trust me. They know I have good decision-making ability."

At his news conference, Mr Trump showed no contrition for any of the controversies he's stirred since joining the presidential race in mid-June.

"I don't think I've made mistakes," he said. "Every time somebody says I made a mistake, they do the polls and my numbers go up, so I guess I haven't made any mistakes."

After answering reporter questions, Mr Trump took a few local children - and two reporters - on helicopter rides.

Mr Sanders, the socialist senator from Vermont challenging Mrs Clinton for the Democratic nomination, made note of a helicopter over the fairgrounds during a speech he was giving.

"I apologize," he joked from the Des Moines Register's political soapbox. "We left the helicopter at home."

While Mr Sanders attracted the largest crowd yet this year at the newspaper's stage, he scored relatively little media attention at the fair.

It's hard to compete with a billionaire celebrity and his helicopter. Even a Clinton learned that lesson on Saturday.