The starting gun on the nomination process for the 2024 U.S. presidential election was fired this week in Iowa, with one big question becoming even bigger: Why is former President Donald Trump so enduringly popular among Republican voters?

There is, of course, no single, simple answer to this question that inevitably arises, especially in the minds of people living outside the United States, be they in Asia, Europe or elsewhere.

Not just in terms of opinion polls, Trump, despite being the first former U.S. president to face criminal charges, proved Monday that he is actually the dominant frontrunner in the Republican nomination race, winning the Iowa caucuses in a landslide.

Trump secured more than 50 percent of the votes in the first-in-the-nation contest, leaving his rivals far behind.

Former U.S. President and Republican presidential candidate Donald Trump speaks at a caucus night party in Des Moines, Iowa, on Jan. 15, 2024. (AP/Kyodo)

When trying to find clues about Trump's strength from his supporters in the Midwest rural state, one issue that was voiced by nearly everyone and stood out the most was illegal immigration, followed by concerns about the economy.

Other Republican candidates challenging Trump have also given a great deal of attention to border security during their campaigns.

But backers of the 77-year-old former president, irrespective of age and gender, appear to have a keener interest in the border issue than those of others, highly praising his initiative to build more physical barriers between the United States and Mexico during his last presidency through January 2021.

It was the case even in the farm-focused state with a population of 3.2 million, which does not border any foreign country or possess diverse racial demographics like many other parts of the country.

"We're a country of immigrants. But as (Trump) said, a lot of countries have dumped their worst citizens right into our country. They're not here to be productive American citizens," Tim Stiles, 59, said. "Generally speaking, we want good quality people coming in who are going to be productive citizens."

Stiles, who works in the financial services sector, said he trusts that Trump will live up to his promise of imposing tougher border controls if he returns to the White House.

He stressed that he is not against foreigners, but against American taxpayers' money being used to help those crossing the U.S. border illegally.

Justin Runge also views illegal immigration and the flow of fentanyl into the United States through the southern border as a central issue in the presidential race.

The 38-year-old electrician said he is concerned that many illegals and drugs are "moving up here" and supportive of Trump's "build the wall" pledge since voting for him in 2016.

Runge said he is confident that Trump will win the November presidential election, possibly against President Joe Biden, who has no formidable Democratic challengers.

"Because he was not a politician when he started," Runge said, when asked to explain the main reason behind Trump's attractiveness to foreign audiences. "He is fighting the establishment...He does not have 'this is how it has to be the type of mindset.' He ran the country like a businessman, not a politician."

Cathy Kurtinitis, 69, who drove her truck about an hour and a half in blizzard conditions to attend a rally event on Sunday, was in favor of almost everything that the former president has done.

"He's kind of bombastic in his speech, but the things that he does are good," said Kurtinitis, wearing a pro-Trump cap.

She called the scores of charges Trump is facing, many of which are related to his attempts to overturn the results of the 2020 presidential election, "stupid" and defended protesters who stormed the Capitol in Washington on Jan. 6 the following year.

She insisted that Trump supporters are "not dangerous. They are not violent. They are Americans who want liberty, freedom and conservative values," while slamming the Biden administration for making the United States and the world "unstable" by what she sees as flawed immigration, economic and foreign policies.

Ixchel Ochoa, a 27-year-old nurse, said more people she knows are now Trump or Republican supporters, pointing out that earning an ordinary living has become increasingly difficult over the last few years for younger generations.

Living together with her boyfriend, who is also a Trump supporter, Ochoa recalled how prices were cheaper when she voted for him twice in the past and criticized the Biden administration for not changing things for the better.

Kristie Wagner, who is in her 40s, shares such concerns for the future and said the country is starkly divided with different realities coexisting.

"The reality (Trump) knows is what a working man or working woman is stepping into, versus a man or woman who has lots of money," Wagner said, noting that the country's middle class is "declining," making it hard for young adults like her son in his mid-20s to afford things by himself.

"We are heading in a direction where it's not looking good," said Wagner, who has a heating and cooling business and regards herself belonging to the middle class. "Even kids are starting to realize that there's something going on."

Wagner said there is no other option than Trump running the country as "you can tell he's cognitive. He can use his common sense. He is not only that, he's a genius."

Mark Jones, a political science professor at Rice University, said every attack against him, every indictment and every criminal charge has helped strengthen his support.

"These (Iowa) results highlight that Donald Trump is the favorite candidate among Republicans," he said. "Trump supporters liked everything he did during his four-year term, or at least most of it."

"They abhor the Biden administration and think the country is going in a completely wrong direction. So they're going to be out there supporting Donald Trump with the hope that he gets the country on what they consider to be the right track."

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