In recent polls, President Trump has reclaimed his position as the frontrunner in the Republican presidential field, recovering from a post-midterm slump and suggesting that 2024 could be a rematch of the 2020 election.

Just weeks after the 2022 midterm election, during which Republicans underperformed expectations, an Ipsos/FiveThirtyEight poll found Governor DeSantis leading Mr. Trump in an open Republican field, 37 percent to 25 percent.

At the time, pollsters were delivering a variety of results, with some showing Mr. DeSantis leading, some showing Mr. Trump leading, and others suggesting the two would garner similar support in a Republican primary.

Now, however, a clear trend is emerging: Mr. Trump is consistently polling ahead of all other candidates in a Republican primary, including Mr. DeSantis.

Morning Consult polling released Tuesday found that Mr. Trump now leads Mr. DeSantis by 13 points, a finding consistent with their other polls over the last month. A caveat to the results is that Mr. DeSantis’s odds consistently improve when it is a face-off between just him and the former president. 

A December 20 Economist poll suggested that Mr. DeSantis would have an eight-point lead in a head-to-head matchup. A Yahoo news poll from around the same time suggested a more modest two-point lead for Mr. DeSantis, but a lead nonetheless.

All of this polling, however, could be moot if Mr. Trump failed to secure the Republican nomination and ran as a third-party candidate. Such a run would split the Republican vote and almost certainly deliver the election to the Democrat in the race.

While Mr. Trump has not publicly discussed that prospect, he did demonstrate that it is on his mind in a little-noticed December 28 Truth Social post linking to an article on the topic in American Greatness. In the article, a professor and conservative pundit, Dan Gelernter, argued that “we’re heading for a 1912-repeat, in which the Republican Party ignores its own voters.”

“The Republican machine has no intention of letting us choose Trump again,” Mr. Gelertnter said. “Do I think Trump can win as a third-party candidate? No. Would I vote for him as a third-party candidate? Yes.”

The resurgent dominance of Mr. Trump over the Republican Party has been demonstrated outside the polls as well, most recently in the House speaker election. Not only did Representative Matt Gaetz cast a vote for Mr. Trump in the seventh round of the election, but Speaker McCarthy specifically thanked Mr. Trump for helping him win votes.

“I do want to especially thank President Trump,” Mr. McCarthy told reporters following the election. “I don’t think anyone should doubt his influence.”

In a general election, polling suggests that Democrats would hold an advantage if Mr. Trump were to become the Republican nominee for 2024. Although pollsters are less consistent in their findings for a general election, the current prevailing trend suggests that President Biden would have a slight edge over Mr. Trump.

A YouGov and Yahoo News poll from December 19 found that Mr. Biden would have a four-point advantage. Similarly, a Fabrizio Lee and Associates/Impact Research and Impact Research poll conducted for the Wall Street Journal found Mr. Biden enjoyed a two-point advantage. Cognizant of this trend and that Mr. Trump’s favorability ratings have been underwater since he left office, many Democrats are sharpening their knives.

Senator Sanders told the New York Times that “as a politician who wants to see that no Republican is elected to the White House in 2024, from that perspective, his candidacy is probably a good thing.”

A former governor of Virginia, Terry McAuliffe, the Democratic National Committee chairman, also expressed hope after the midterms that Mr. Trump would run again. “I think we would all like Donald Trump to run again,” Mr. McAuliffe told Gray’s Washington News Bureau. “He literally helped hand us the great victories.”

On the Democratic side, it is becoming increasingly clearer that Mr. Biden intends to run for re-election, as the president has repeatedly said so and messaging from the White House pivots to touting the administration’s achievements.

Although no official announcement has been made yet, legislators and administration officials have all but confirmed that he will be running in 2024 and will in all likelihood receive the Democratic nomination.