Following Governor DeSantis’s landslide re-election in Florida, Republicans are racing to crown him as the man to lead them out of the wilderness in 2024. They can’t, though, ignore the fact that refugees from blue states helped boost the governor’s showing at the polls, a factor that won’t benefit him on the national map and that might even make his path harder.

Mr. DeSantis is not a declared candidate, but Republicans hope he can replicate his state’s red wave, which saw all Democrats swept from statewide office for the first time since Reconstruction. There’s no denying he’s an effective leader and talented political operator, skills that enabled him to increase his 34,000-vote victory margin in 2018 to 1.5 million in 2022.

A lot changed in the four years between the elections, though. The state saw a huge influx of residents as citizens fleeing draconian Covid-19 policies and high taxes in Democratic states made Florida their top destination. Between April 2020 and April 2021 alone, almost 330,000 people headed south.

Most of these newcomers likely supported Mr. DeSantis. After the father-in-law of Governor Newsom of California, Kenneth Siebel, relocated to the Sunshine State with his wife, his family trust donated $5,000 to the Friends of Ron DeSantis PAC.

Such factors could make Mr. DeSantis a lock for his state’s 30 electoral votes, even against President Trump, but he’d need to pick up more elsewhere to hit the magic number of 270. It’s here that he could pay the price for so many people flocking to Florida — because they’ll no longer be available to support him elsewhere.

A few thousand votes can decide if the Marine Band plays “Hail to the Chief” when you enter a room. “[J]ust 44,000 votes in Georgia, Arizona, and Wisconsin,” NPR’s Domenico Montanaro said, “separated Biden and Trump from a tie in the Electoral College” showdown of 2020.

That would’ve sent the choice to the House, where each state gets a single vote and Republicans, holding a lead in delegations, would have given Mr. Trump a second term. The numbers were almost as close in the 2016 upset over Secretary Clinton, which also came down to a razor’s edge in key states.

According to Cook Political’s Dave Wasserman, Mrs. Clinton lost Michigan, Pennsylvania, and Wisconsin — 46 electoral votes of her 74-vote shortfall — by 10,704, 46,765, and 22,177 ballots, all less than 1 percent. Had she flipped those three, she’d have been sworn into the Oval Office on Inauguration Day.

The 2000 Democratic nominee, Vice President Gore, faced the narrowest loss of all. He would have prevailed had 540 people swung his way in Florida, or had he been the choice for his home state of Tennessee, which President George W. Bush carried for the Republican ticket by 80,000 votes.

One tactic that Mr. DeSantis used to build his 2022 landslide will be crucial if he’s going to replace the voters who moved to Florida from competitive states and give himself a fighting chance in a 2024 campaign, and that’s voter registration.

In Florida, the GOP “caught and surpassed” its rivals“for the first time in the modern history of the state,” Gary Fineout wrote in Politico last month. “In November 2021, there were 6,035 more active registered Republicans than Democrats. That gap has now ballooned to 305,590.”

Nationwide, Democrats still hold a registration advantage of 48 million to 36.4 million over Republicans, a number about equal to the population of Ohio. The job of closing that gap, as Mr. DeSantis did on the local level, will fall to state and national GOP machines. Their task will be made easier in the event President Biden remains unpopular and the new Republican majority in the House of Representatives delivers for the American people on inflation and other challenges.

If Mr. DeSantis seeks the presidency, it will require more of the hard work and delivering on issues that earned him his landslide. Do that, and he’ll convince Americans that they don’t have to move to Florida for a brighter future. They can simply vote to move him into the White House.