These top 5 moments from the presidential campaign trail in 2023 defined the Republican primary race

What a difference a year makes.

At the dawn of 2023, former President Donald Trump was the only declared candidate in the race for the Republican nomination.

But he was far from a sure thing. 

Florida Gov. Ron DeSantis, fresh off an overwhelming gubernatorial re-election less than two months earlier, was neck and neck with Trump in some of the early 2024 polls. 

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The former president was still facing criticism for contributing to the GOP's lackluster performance in the 2022 midterms.

And Trump's 2024 presidential campaign launch at his Mar-a-Lago club in Palm Beach, Florida, a couple of weeks after the midterms was panned by many pundits.

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But as 2023 comes to a close, Trump is the commanding frontrunner for the Republican nomination as he makes his third straight White House bid.

Here are five moments that shaped the showdown for the Republican nomination.

Trump was indicted by a grand jury in the New York City borough of Manhattan on charges related to an alleged illegal 2016 hush money payment. Trump made history as the first former or current president to be indicted for a crime.

Trump was also indicted later in the year in three other cases, including charges he tried to overturn his 2020 presidential election loss. But those cases have not deterred his support among Republican voters.

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Trump's legal controversies have had a rallying effect among Republicans, and his legal entanglements have sucked the oxygen out of the room for his nomination rivals.

"Every time he's targeted by legal actions, it just improves his standing with the conservative base," longtime Republican strategist and communicator Ryan Williams said.

DeSantis, in an interview that aired on the Christian Broadcasting Network a couple of days ago, argued that "I think for the primary, it distorted. Yeah, I think it distorted."

"I would say if I could have one thing change, I wish Trump hadn’t been indicted on any of this stuff," DeSantis emphasized.

After months of testing the waters with trips to the crucial early voting states, DeSantis aimed to make waves with his campaign launch on Twitter Spaces with Elon Musk.

But it didn't go as planned.

X, then still called Twitter, couldn't handle the surge in traffic, the app repeatedly crashed and the event eventually started 20 minutes late.

It was the first of many bad omens for DeSantis.

The Florida governor made headlines again for all the wrong reasons over the summer, with a series of campaign staff purges and resets and reports of the campaign burning through cash. 

There were more staff shakeups in autumn, this time at the DeSantis-aligned super PAC Never Back Down, which had taken over many of the traditional duties of a presidential campaign, including grassroots outreach.

DeSantis for months was the clear No. 2 rival to Trump in the Republican nomination race. But in many metrics, Nikki Haley, the former ambassador to the United Nations and former South Carolina governor, had surpassed DeSantis for second place by the end of 2023.

As he ran an incumbent-style campaign, Trump decided against sharing the debate stage with his GOP rivals.

"The public knows who I am & what a successful Presidency I had," Trump wrote on his social media site ahead of the first debate in August. "I WILL THEREFORE NOT BE DOING THE DEBATES!"

The former president ended up skipping all four candidate showdowns held this year while hosting competing events on the debate nights.

Trump's absence didn't seem to hurt him. He emerged relatively unscathed by his rivals, and his lead over the rest of the field has only grown since the first debate was held.

While the debates didn't affect Trump, they did help winnow the field of contenders, as nearly all the candidates who failed to qualify for the showdowns dropped out of race. A field of more than a dozen candidates in August was down to just five major contenders by December.

As summer turned into autumn, speculation and buzz about Virginia Gov. Glenn Youngkin potentially making a late entry into the 2024 GOP nomination race was the talk of the party's donor class.

As a first-time candidate from the party’s business wing, Youngkin edged out former Democratic Gov. Terry McAuliffe in 2021 to become the first GOP candidate in a dozen years to win a gubernatorial election in the one-time swing state that had trended toward the Democrats the previous decade.

Youngkin became an instant Republican Party star, and pundits immediately viewed him as a potential GOP 2024 contender. 

But Youngkin dismissed the speculation, and he repeatedly said his only political mission was to win outright control of his state legislature in Virgnia's 2023 off-year elections.

After investing plenty of political capital on behalf of Republican legislative candidates as he criss-crossed the state holding rallies, Youngkin became the face of his party's push to win total control of the state government in Richmond. 

But he failed in his mission, and the buzz about Youngkin parachuting into the White House race instantly dissipated.

Haley enjoyed plenty of momentum in the polls this autumn, thanks in part to well-received performances in the first three Republican presidential primary debates. 

She leapfrogged DeSantis for second place in New Hampshire, which holds the first primary and votes second after Iowa. And she's in second place in her home state, another crucial early voting state that holds the first southern contest.

But things accelerated for Haley soon after Thanksgiving.

That's when she was endorsed by Americans for Prosperity (AFP) Action, the political wing of the influential and deep-pocketed fiscally conservative network founded by the billionaire Koch Brothers. AFP Action has pledged to spend tens of millions of dollars and mobilize its formidable grassroots operation to boost Haley and help push the Republican Party past Trump.

A couple of weeks later, Haley landed the much coveted endorsement of popular Republican Gov. Chris Sununu of New Hampshire, who spent three straight days teaming up with her on the campaign trail in the Granite State.

The governor’s endorsement of Haley appeared to give her campaign an extra boost as well as a high-profile and energetic surrogate who has been tireless in touting her during national and local media appearances.

It all seems to be clicking for Haley. She's soared in the latest polls in New Hampshire and is now within striking distance of Trump. 

And in Iowa, whose Jan. 15 caucuses lead off the GOP nominating calendar, she's pulled even with DeSantis.

Get the latest updates from the 2024 campaign trail, exclusive interviews and more at our Fox News Digital election hub.