'I'm angry, but I'm really mostly scared': Fear and anger fuel Donald Trump fans on the campaign trail
US Republican presidential frontrunner Donald Trump talks to students and other supporters at a high school in Urbandale, Iowa, on September 19, 2015 (AFP Photo/Michael Mathes)

President Barack Obama is weak, the United States needs a bold anti-politician not beholden to special interests, and the losers running Washington must be ousted once and for all.

So say a dedicated but seemingly growing band of voters who are shunning a Republican establishment desperate to regain the White House, opting instead for a brash, uncompromising and headstrong celebrity who can revive the nation's mojo.

"Donald Trump is standing up for what Americans want," said Kim Tyrrell, 35.

"He knows what's going on in America and he will do the best to protect us."

Tyrrell was first in line to see the real estate tycoon at a rally Saturday at Urbandale High School in Iowa, where a dozen supporters -- and a few voters who remain wary of the blunt billionaire -- shared their thoughts about the controversial candidate who has rocketed to the top of the Republican heap.

In interviews with AFP both at the rally and at another, faith-based event in nearby Des Moines where Trump and other Republican presidential hopefuls spoke, most acknowledged he has been light on his specific plans should he win the White House.

But supporter Mary Butler said many conservatives, furious over Republican leadership's failures in Washington, are not concerned about that just yet.

"They want to see fresh blood. They don't want to see somebody that's been around the horn for how many years in politics," she said.

Butler is rooting for Trump, she said, "because he has the smarts, the know-how to run his businesses," and understands what is at stake: "Running this country, (defeating) the Taliban and ISIS. You know, that kind of thing."

- 'Get them out' -

Doug Ott, 55, expressed frustration at the millions of immigrants living in the United States illegally.

The Iowan backed Trump's vow to build a wall on the US-Mexico border, part of an immigration plan criticized by some as xenophobic, especially after Trump called some Mexican immigrants "rapists."

"The wall is what we need," Ott said.

"Give them work permits, I don't mind that," he added. "But when they're over, get them out."

Many Trump supporters condemned Obama as a disaster. And they appeared unfazed about Trump's never-ending personal attacks on rivals or supersized claims, including that he would be "the greatest jobs president that God has ever created."

"I think he just brings more backbone than what we've seen in other candidates," explained Grace Swanson.

Asked if she thinks Trump's bull-in-a-China-shop style is right for the White House, where Republican hero Ronald Reagan compromised with his adversaries at home and abroad a generation earlier, Swanson paused: "Maybe we've just had too much compromise," she said.

Trump has tapped into a sentiment among many conservative voters that the United States under Obama is careening down the wrong path.

"I'm angry, but I'm really mostly scared," said Dan Edwards, who no longer works because of a disability.

He wants Trump to head to Washington to play hardball.

"We (Republicans) won the House and Senate, and nothing got done," he fumed.

"It was like, are you kidding me? That was the last straw. So now we're looking for someone who'll clean house."

- 'Bring Christianity back' -

Rivals have bristled at Trump's claims of conservative fidelity, arguing that he espoused Democratic principles on abortion and taxes before he shifted to the right.

But even undecided conservatives indicated that such shifts signal personal growth, not political flip-flopping.

"I love what Trump is doing in our party right now," said Wendell Steven, the Republican Party chairman in Iowa's Kossuth County, who wants to study Trump more closely before committing to him.

"He's shaking it up, and that's what we all appreciate," he added. "We've got to get this turned around or our country goes down the tubes."

Several supporters including Tyrrell pointed to Trump's Christian faith, although she admitted she knows little about "his religious side."

But she insisted: "We need to bring Christianity back into the United States."

Many appeared to be putting blind faith in a man they hold up as the ultimate winner.

"Pretty much everything that he says, he's struck a chord," said unemployed Urbandale native Kevin McNeal, 57, who lounged in a beach chair in the near-twilight to watch Trump.

The 1,000-strong Urbandale crowd -- small by Trump standards -- gave him a rock star welcome as he slapped high fives with students. Supporters snapped selfies in front of a blue Trump campaign bus.

But not all were enamored by "The Donald."

Realtor Deb Miller revealed she is "not a huge fan" and is likely to vote for a "more qualified" candidate.

But even she agreed with supporters in conceding that Trump's personal fortune frees him from the typical donor-politician relationship that traps candidates.

"He doesn't owe anybody anything. He's not beholden to anybody," she said.