Donald Trump secured a landslide victory in the opening contest for the Republican presidential nomination in Iowa on Monday, reinforcing his determination to clinch the November election and revive his "America First" policy.

The former president won by a record margin for an Iowa caucus, receiving 51.1 percent of nearly all the votes counted, followed by Florida Gov. Ron DeSantis with 21.2 percent, while former U.N. Ambassador Nikki Haley garnered 19.1 percent, according to the Republican Party of the Midwest state.

Trump said his win by an overwhelming margin, was an "incredible experience."

Former U.S. President Donald Trump speaks during a visit to a caucus site in Clive, Iowa, on Jan. 15, 2024, as Iowans vote in the state's caucuses for the first-in-the-nation Republican nomination contest. (Getty/Kyodo)

"We're going to put America first. We're going to make America great again," Trump said in a victory speech in Des Moines to his campaign team and supporters. "The big night is going to be in November when we take back our country."

With the Iowa caucuses, the nomination process for the election formally began. All eyes are on whether any remaining challengers stand a chance against Trump in the months-long process.

Amid conditions that have seen blizzards and temperatures that dropped to about minus 30 C in recent days, Republicans in the rural state expressed their preferences at more than 1,600 sites, including school gyms and churches, across 99 counties.

The caucuses, held in the coldest weather since it was established as the first in the nation in the 1970s, come as the 77-year-old former president holds a lead of about 50 percentage points over his closest rivals in national polls.

Observers were keen to see whether Trump's huge polling lead would translate into votes and to what extent his top challengers could gain ground.

DeSantis, 45, whose campaign has struggled for months, and Haley, 51, whose momentum has been growing in recent weeks, were neck-and-neck for second place, vying to win the hearts of uncommitted Republicans.

"Because of your support, in spite of all of that they threw at us, everyone against us, we've got our ticket punched out of Iowa," DeSantis said late Monday night.

Haley also told a crowd of supporters that she will keep fighting for the nomination, asking them, "Do you want more of the same, or do you want a new generation of conservative leadership?"

Entrepreneur Vivek Ramaswamy, 38, who was a distant fourth, decided to pull out of the presidential race after the result and went on to endorse Trump.

Former Arkansas Gov. Asa Hutchinson, 73, also withdrew from the race after he received only 0.2 percent of the votes in the caucuses.

Photo taken on Jan. 15, 2024, in Des Moines, Iowa, shows a signboard appealing for voters to support former U.S. President Donald Trump as the nomination process for the presidential election in November formally begins the same day, with Republicans in the Midwest rural state expressing their preferences at precinct meetings. (Kyodo) ==Kyodo

Despite facing 91 criminal charges in four separate cases, Trump has retained a committed following. According to polls, he also leads President Joe Biden in some key battleground states, raising doubts about whether the Democratic incumbent can secure a second term.

Biden entered 2024 -- a year that will chart the direction of the United States and most likely the world in the near future -- with persistently low approval ratings.

The Iowa Republican presidential caucuses awarded 40 delegates to the party's national convention. The first nominating contest, followed by New Hampshire on Jan. 23, represents only a very small number of the total 2,429 Republican delegates up for grabs, yet it has long exerted a major influence on subsequent primary and caucus results.

History has shown that the eventual nominee almost always wins Iowa or New Hampshire or at least beats expectations in one of the two states.

The two main parties nominate a presidential candidate through a string of state primaries and caucuses held until their respective conventions in the summer.

Yet the Republican Party's choice may become apparent with the results of "Super Tuesday" on March 5, when more than a dozen states will hold primary contests.

Unlike primaries, which are akin to ordinary elections, caucuses require voters to gather at a specific time to discuss their preferences publicly.

In a change from past practices, the Democratic National Committee has made South Carolina its first nominating contest on Feb. 3, followed by Nevada on Feb. 6.

The move followed Biden's request that his party's nomination calendar prioritize states that are more racially diverse than Iowa and New Hampshire, whose populations are each about 90 percent non-Hispanic whites.

Iowa is notably less urban than the rest of the United States. Des Moines, the state's capital, has a population of just over 200,000.

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