Republican presidential candidate Donald Trump greets fairgoers while campaigning at the Iowa State Fair on August 15, 2015 in Des Moines, Iowa
Washington (AFP) - It is home to just one percent of Americans, lacks ethnic diversity and hosts an impenetrable voting system. So why does Iowa remain such an important presidential campaign ground?
Simply put, Iowa's caucuses are first. With its residents casting the debut votes in the 2016 race, all eyes are already on the Hawkeye State, and it will stay that way until caucus day, likely February 1.
Most of the 17 Republican and five Democratic White House hopefuls have already descended multiple times on the folksy heartland. Nearly all are attending the Iowa State Fair, currently in full swing and offering candidates massive media exposure while getting up close with voters.
It is a rite of political passage: eat pork on a stick, admire butter sculptures and face pointed questions from voters, all in front of national reporters eager to assess how candidates are faring early on.
"We intend to be here often," Republican Senator Marco Rubio promised Tuesday from the fair's "soapbox" stage.
Iowa is immensely consequential for candidates, and it takes its presidential vetting role seriously.
"It's kind of a madhouse," David Redlawsk, a political science professor at Rutgers University who wrote a book about the Iowa caucuses, told AFP from the fair.
"The crowds, the media scrum, the interest in the soapbox. It's beyond anything we've seen," he added.
Campaign spin machines aside, Iowa is about intimate encounters with voters on front porches, in coffee shops and church basements.
It is a study in imperfect electoral math and inconvenient precinct caucuses that bar absentee voting and frustrate participants with quirky rules.
Despite its system, "you have to really admire Iowa," said Joseph Lane, an Emory & Henry College professor who has studied the caucuses since 2000.
"They have managed to make people work with voters on a much more individual basis than has survived almost anywhere else in the United States," Lane said.
Iowa's image remains powerful in American lore: idyllic small-town life where faith, common sense and an open-hearted warmth prevail.
"There's a nostalgia associated with Iowa that goes beyond the political process," observed Jeff Coleman, a one-time Pennsylvania state legislator.
"It is America as many people remember it, and the America that many people would like to have back."
He insisted that despite technological transformations, Iowa remains necessary because it "slows the process down."
Coleman supports Rick Santorum, the conservative ex-senator who visited all 99 Iowa counties in a pickup truck in 2011. He narrowly beat Mitt Romney in Iowa, only to finish runner-up to Romney for the nomination.
Capturing lightning in a bottle again is unlikely -- Santorum is polling at barely one percent, steamrolled by better-known candidates.
But his improbable win four years ago proved his own words: "Money doesn't buy Iowa," he said in 2012. "Hard work, good ideas, strong principles" do.
- Iowa delivers -
Iowa cemented its first-in-the-nation status quite by accident.
In 1972 the Democratic Party democratized its primary process. Iowa's organizers, determining they needed months for their convoluted system to play out, leapfrogged ahead of New Hampshire, which had opened the nominating process for decades.
No one took much notice until the 1976 cycle, when an obscure southern governor, Jimmy Carter, barnstormed Iowa and won, catapulting him to the nomination and ultimately the White House.
Candidates from both parties have beaten a path to Iowa since, and a political adage congealed: "There are three tickets out of Iowa." The top three advance, losers go home.
Narrowing the current field will be a tall order, especially on the 17-strong Republican side. "It is the most challenging job of winnowing they've ever faced," said Iowa State University professor Steffen Schmidt.
Iowa is an especially homogenous state in an increasingly diverse nation, and criticism has simmered that it gloms onto national trends -- billionaire Donald Trump currently leads in Iowa polling -- instead of engaging in sound presidential vetting.
Efforts to oust Iowa from its privileged perch come and go.
"The problem is, nobody is agreed on who will replace it," said Peverill Squire of the University of Missouri.
The Iowa caucuses, he added, are "one of America's great civic events."
The Democratic National Committee agrees, with an official telling AFP it has "no intention to switch things up."
New Hampshire votes close on Iowa's heels. South Carolina and Nevada have moved their primaries forward to ensure a broader early spotlight.
But Schmidt has a message for states that want to supplant his state.
"Stop whining," he chuckled. "If you want to be first, come up with a good reason."
Schmidt pointed to Iowa's record of teasing "grassroots honesty" from candidates, whittling down the field and often picking the eventual president, from Carter to George W. Bush to Barack Obama.
"Iowa," he said, "has delivered."