Could Ron DeSantis Be Trump’s G.O.P. Heir? He’s Certainly Trying.

MIAMI — No one had to tell Ron DeSantis that his mock debates had bordered on disastrous. His answers rambled. He seemed uninspired.

By the time he got to the greenroom of the biggest political stage of his career, a Republican primary debate for Florida governor in June 2018, he had made a risky decision.

“I thought about everything we did in debate practice,” his campaign manager, Brad Herold, recalled Mr. DeSantis’s telling him. “I’m going to throw it out and do my own thing.”

At the debate’s start, the audience applauded louder for his better-known opponent, Adam Putnam. By its end — after he had cast Mr. Putnam as a vestige of old Republicanism and delivered a rat-a-tat of one-liners — Mr. DeSantis had taken command of the crowd.

Nearly three years and a pandemic later, Mr. DeSantis’s inclination to keep his own counsel and drive hard at reopening Florida has made him perhaps the most recognizable Republican governor in the country and a favorite of the party faithful. In turn, he has become a polarizing leader in the resistance to lengthy pandemic lockdowns, ignoring the advice of some public health experts in ways that have left his state’s residents bitterly divided over the costs and benefits of his actions.

Now, with Florida defying many of the gloomy projections of early 2020 and feeling closer to normal as the pandemic continues to dictate daily life in many other big states, Mr. DeSantis, 42, has positioned himself as the head of “the free state of Florida” and as a political heir to former President Donald J. Trump. Mr. DeSantis owes a mightier debt than most in his party to Mr. Trump, who blessed his candidacy when he was a nobody congressman taking on the staid Florida Republican Party.

Mr. DeSantis’s political maneuvering and extensive national donor network have allowed him to emerge as a top Republican candidate to succeed Mr. Trump on the ballot in 2024 if the former president does not run again. The governor’s brand of libertarianism — or “competent Trumpism,” as one ally called it — is on the ascent. Seizing on conservative issues du jour like opposition to social media “censorship” and vaccine passports, he has forged strong connections with his party’s base.

And his bonds with Republican leaders may be deepening: Mr. DeSantis has a plum speaking spot on Saturday night at Mar-a-Lago, Mr. Trump’s resort and political base in Palm Beach, Fla., for the Republican National Committee’s spring retreat. Other possible 2024 rivals, like former Secretary of State Mike Pompeo and Senator Marco Rubio, were relegated to appearances a night earlier.

The governor has also taken steps to shore up his political standing around his handling of the pandemic, summoning reporters to the State Capitol on Wednesday to blast — complete with a slide-show presentation titled “FACTS VS. SMEARS” — a report in CBS News’s “60 Minutes” that did not have sufficient evidence to prove a pay-to-play dynamic between Mr. DeSantis’s administration and Covid-19 vaccine distribution for white and wealthy Floridians.

His record on the virus is, in fact, mixed. By some measures, Florida has had an average performance in a pandemic that is not yet over. Yet his decisions helped keep hospitals from becoming overwhelmed with coronavirus patients. He highlights that he helped businesses survive and allowed children to go to school.

What his critics cannot forget, however, is how he resisted some key public health guidelines. An op-ed article endorsing masks that his staff drafted under his name in mid-July was never approved by the governor for publication. The restrictions he now dismisses as ineffective, such as local mask mandates and curfews, which experts say in fact worked, were imposed in most cases by Democratic mayors with whom he hardly speaks.

Given the ways people admire or despise him, however, the nuances seem beside the point.

He infuriates passionate critics who believe he operates shrewdly to tend to his own interests. They fear that approach contributed to confusing public health messages, vaccine favoritism for the wealthy and the deaths of about 34,000 Floridians. “DeathSantis,” they call him. (Mr. DeSantis declined repeated interview requests for this article.)

But at almost every turn, Mr. DeSantis has seized the criticism as an opportunity to become an avatar for national conservatives who relish the governor’s combativeness. He can score points that his potential Republican rivals in the minority in Washington, including Mr. Rubio and Senator Rick Scott, his predecessor as governor, cannot.

“He’s taken the wrong approach on some of our most critical issues, Covid being first and foremost, yet within Republican political circles, he is considered to be the front-runner for the White House,” said former Representative David Jolly, an ex-Republican who is flirting with a possible run for governor. “He’s worked his hand perfectly.”

Mr. DeSantis has raised his profile despite lacking the gregarious personality that might be associated with an aspiring Trump successor. Unlike the former president, no one would describe the publicly unemotional and not especially eloquent Mr. DeSantis as a showman. (After a record day of coronavirus deaths in July, he offered, “These are tough, tough things to see.”) People close to him describe an un-Trump-like fondness for poring over articles in scientific journals.

And, they say, do not underestimate the intellect and instinct that have repeatedly defied expectations and propelled Mr. DeSantis from Little Leaguer in middle-class Dunedin, Fla., to potential presidential contender.

“He has a set of skills and traits that are ideal for the times,” said former Representative Carlos Curbelo, a Republican who served in the House with Mr. DeSantis. “Today, it would be very difficult to defeat him.”

A long athletic, military and political résumé

He pronounces his last name “DEE-san-tis.” On the baseball field, he went simply by “D.”

His team from Dunedin, on Florida’s Gulf Coast, made it to the Little League World Series in 1991. He was a 12-year-old known to be serious and competitive.

His father installed Nielsen TV-ratings boxes. His mother was a nurse. When he went to Yale, the Florida native — he was born in Jacksonville — arrived on campus in cutoff denim shorts.

“One of the reasons we got along is we weren’t the traditional, Ivy-League-mold students,” said Nick Sinatra, a former Delta Kappa Epsilon fraternity housemate. “He always talked politics. I’m a conservative, and at a place like that, that’s not common.”

A history major, Mr. DeSantis lugged around a backpack full of books. He studied for both academics and athletics, scrutinizing ballplayers on TV. The Yale baseball team elected him captain.

His résumé got only more sterling. He spent a year teaching history at a Georgia prep school before landing at Harvard Law. He received a commission in the Navy’s Judge Advocate General’s Corps, where he served at Guantánamo Bay (“not as a detainee, as an officer,” he has quipped) and in Iraq. For two years, he worked as a federal prosecutor before winning a congressional seat near Jacksonville in 2012. His 2011 book, “Dreams From Our Founding Fathers,” which laid out a stridently conservative ideology, made him popular among Florida Tea Party Republicans.

Two years earlier, he had married Casey Black, a local television anchor he met on a driving range. Ms. DeSantis would become one of her husband’s closest advisers and biggest political assets, with an office at the State Capitol. They have three children under the age of 5; the youngest was born in March 2020. Mr. DeSantis said he was not in the delivery room so as to avoid using up precious personal protective equipment.

The most memorable part of Mr. DeSantis’s six years in Congress might be the platform they gave him to heighten his profile on Fox News, where he frequently represented the hard-line Freedom Caucus. Later, he would staunchly defend Mr. Trump over the Russia investigation.

“He was a policy wonk with an ability to really identify a few areas within his committees, responsibilities which he knew would give him the political opportunity to get on television,” said Scott Parkinson, who was Mr. DeSantis’s chief of staff in 2018. Mr. DeSantis was appearing on cable TV multiple times a day, Mr. Parkinson recalled.

Mr. DeSantis often slept in his office and walked the Capitol halls wearing headphones, avoiding unwanted interactions. He made few friends and struck other lawmakers as aloof.

A brief Senate run in 2016 proved critical: It exposed him to a national network of wealthy donors he would later tap in his long-shot bid for governor.

Mr. DeSantis barely defeated Andrew Gillum, at the time considered one of the Democrats’ brightest stars, after a bruising campaign laced with accusations of racism. Determined to show his independence in his first months in office, he appointed a chief science officer and pledged billions for the Everglades. He pardoned four wrongfully accused Black men. He lifted a ban on medical marijuana in smokable form.

He was hardly a moderate: Mr. DeSantis also gutted a voter-approved measure meant to restore felons’ right to vote. He allowed some teachers to carry guns in schools. He banned so-called sanctuary cities in a state where there were none.

But the mix pleased voters, and his approval ratings surged. Might the man who had shown his diaper-age daughter building a wall in a campaign ad actually be a pragmatist?

Then came the pandemic.

Defiant leadership during a crisis

In a state where political consultants often become synonymous with their clients over time, Mr. DeSantis has cycled quickly through advisers. A close friend and transition deputy was Representative Matt Gaetz, who is now embroiled in a scandalous federal investigation.

Mr. DeSantis centralized power in his office early in the pandemic, ceding little of the spotlight to public health officials. The state Department of Health’s weekly Covid-19 recaps are titled “Updates on Florida’s Vaccination Efforts Under Governor DeSantis’ Leadership.”

Mr. DeSantis’s slowness in locking down the state last year hurt his approval ratings. So did a deadly summer surge of the virus. But then, far earlier than most other governors, he pledged that schools would open in the fall and life would start returning to normal.

“His policies were contrarian, and he was defiant,” said Tony Fabrizio, a Republican pollster who has tracked Mr. DeSantis’s popularity and saw it rebound beginning last summer. “The more he stands his ground, the more he speaks his mind, the more the affinity grows for him.”

His critics see the governor as stubborn and unwilling to hear dissent.

“The governor we have today is the governor we anticipated after the election,” said Nikki Fried, Florida’s agriculture commissioner and the only Democrat elected statewide, who looks likely to run against Mr. DeSantis.

“He surprised everybody in 2019,” she added, “but obviously that is not truly who he is.”

In some ways, Mr. DeSantis has filled the void left by Mr. Trump, minus the tweets. He remains a Fox News regular. He counts among his scientific advisers Dr. Scott W. Atlas, the former Trump adviser who has promoted dubious theories. Mr. DeSantis’s office said he had received a vaccine last week but not in public, reminiscent of Mr. Trump, who was given the shot behind closed doors.

And the governor’s favorite foes are the “corporate media,” against whom he has scored political points.

His recent tangle with “60 Minutes” centered on the extent to which political connections have helped white, wealthy Floridians get vaccinated.

Local news outlets have chronicled how vaccine access has been slower for Black, Latino and poorer communities. Some pop-up vaccination sites were opened in neighborhoods that had many older residents — and that also had ties to DeSantis campaign donors.

But “60 Minutes” focused on how Publix supermarket pharmacies received doses and left out relevant details, including an extended response from the governor at a news conference.

On Wednesday, in Mr. DeSantis’s words, he “hit them back right between the eyes,” accusing “60 Minutes” of pursuing a malicious narrative.

He left without taking questions.

Research was contributed by Susan C. Beachy, Kitty Bennett and Alain Delaquérière.