The end of Labor Day weekend would typically mark the start of a furious sprint to the Iowa caucuses as candidates battle for their party’s presidential nomination. But as the 2024 campaign comes into greater focus, the usual frenzy is yielding to a sense of inevitability.

Among Republicans, President Trump is dominating the primary field, outpacing rivals with resumes as governors, diplomats and entrepreneurs that would normally prove compelling. 

The 45th president’s strength comes despite — or perhaps because of — multiple criminal indictments that threaten to overshadow any serious debate about the future of the country. 

And for now, the tens of millions of dollars that Republican rivals are pouring into the race are doing little to diminish Mr. Trump’s stature, fueling concerns among his GOP critics who fear the primary is essentially over before it begins.

As one troubled front-runner tightens his grip on the Republican nomination, President Biden is on a glide path to victory on the Democratic side. The 80-year-old incumbent is facing only token opposition for the Democratic nomination despite concerns about his age and performance from many within his own party.

Whether voters like it or not, a Trump-Biden rematch may be on the horizon, raising the prospect of a deeply uncertain election season that only intensifies the nation’s political divide. 

Already, Mr. Trump is skipping his party’s presidential debates and his court appearances are sometimes drawing more attention than his campaign stops. And Mr. Biden has barely begun to campaign as he grapples with questions about his age and his son’s legal challenges.

“I just can’t imagine things markedly changing. So, it appears that past is prologue,” Governor Newsom of California, a Democrat, said in an interview, praising Mr. Biden’s record of achievement while warning his party against underestimating Mr. Trump’s political strength.

Mr. Newsom said concerns about Mr. Biden’s age “are fair game and the White House knows it.”

”But if age equals results,” he went on, “I’m looking forward to his 85th birthday.”

On the Republican side, dread is building among some donors and party leaders who hoped conservative voters would move past Mr. Trump given the January 6 attack on the Capitol he inspired and his serious legal challenges.

“A Trump-Biden rematch would be a disaster for the country. I’m very depressed about it,” said a prominent Republican donor, Bobbie Kilberg, who is supporting former Governor Christie. She said it’s “scary” that so many voters in her party continue to support the former president. ”I refuse to believe that Trump is our inevitable nominee.”

There is time for the 2024 landscape to shift.

Four months remain before the first votes are cast in the Iowa caucuses and the general election is more than a year away. And recent history has plenty of examples of overlooked and seemingly overmatched candidates who proved the conventional wisdom wrong. Both Messrs. Trump and Biden are among them.

There are also significant variables.

Abortion continues to scramble elections — even in GOP strongholds like Kansas, Kentucky, and Ohio — as voters reject Republican efforts to restrict access to the procedure. A greater backlash is possible as the courts review access to a commonly used abortion pill.

And Trump is facing 91 felony charges in criminal proceedings unfolding at Washington, New York, Miami and Atlanta. They involve everything from his handling of classified information to his efforts to overturn the 2020 election to orchestrating hush money payments to a porn actor.

The former president could be a convicted felon before the general election is decided next November. Still, party leaders — including most of his Republican primary opponents — have vowed to support him even if he’s convicted. And nothing in the Constitution bars felons from assuming the presidency.

At the same time, Democratic officials are deeply concerned about the prospect of a third-party bid under the banner of No Labels, a centrist group backed by a $70 million budget working to secure a place on the presidential ballot in at least 20 states this year.

Group leaders insist they would nominate a candidate next spring only as “an insurance policy” should Messrs. Trump and Biden win their respective primaries, which appears increasingly likely. And then, No Labels would move forward only if it’s certain that its presidential nominee wouldn’t unintentionally help Mr. Trump win reelection.

Democratic leaders aren’t convinced.

Several current and former elected officials have been in close contact with the organization, including Senator Manchin, the West Virginia Democrat; a former Utah governor, Jon Huntsman; and Governor Hogan of Maryland.

Senator Cassidy, a Louisiana Republican who says he supports No Labels’ mission, did not rule out running as a No Labels presidential contender himself when asked during a recent interview.

“I don’t want No Labels to run a candidate. I want the two parties to respond responsibly to the challenges before us,” Dr. Cassidy said, indicating he wouldn’t support Mr. Trump or Mr. Biden. He described a presidential bid of his own under the No Labels banner as a hypothetical he didn’t want to comment on.

In ruling out Mr. Trump, the Louisiana Republican cited the criminal charges against the Republican former president, questions about his viability in the general election, and the former president’s refusal to “be honest with the American people” about looming budget shortfalls in Social Security and Medicare.

Dr. Cassidy also raised concerns about Mr. Biden’s physical and mental health. “He’s just so obviously declining,” he said.

Indeed, both Trump and Biden have glaring liabilities, according to a new poll by the Associated Press-NORC Center for Public Affairs Research.

Mr. Biden is “old” and “confused,” and Mr. Trump is “corrupt” and “dishonest.” Those were among the top terms Americans use when asked to describe each party’s leading presidential candidates.

Yet leaders in both parties are willing to overlook such problems.

The Young Democrats of America president, Quentin Wathum-Ocama, concedes that young voters aren’t necessarily enthusiastic about a Trump-Biden rematch, but he hopes that M.r Trump’s polarizing candidacy will give Mr. Wathum-Ocama’s party the energy Mr. Biden cannot.

“Yes, people want a younger generation of politicians. We’ve always talked about Joe Biden as — even he’s said — as a transitional figure in our political life,” he said. ”As much as we’re seeing folks, for whatever reason, may not be excited or whatever, to me, it comes back to democracy is on the line.”

With virtually no exceptions, Democratic officials in Congress and in key states are publicly rallying behind Mr. Biden’s reelection.

Senator Sanders, Mr. Biden’s strongest challenger in the 2020 Democratic primary, endorsed Mr. Biden’s reelection bid hours after it was announced this spring. Mr. Biden enlisted other would-be rivals for his national advisory board. The group includes Representative Ro Khanna, Governor Pritzker of Illinois and Mr. Newsom.

Republicans have delighted in suggesting that Mr. Newsom plans to launch a primary challenge against Mr. Biden, something the Coast governor has repeatedly ruled out. 

That’s even as Mr. Newsom teases the possibility of a high-profile debate against Governor DeSantis, who is among Mr. Trump’s top Republican challengers.

Mr. Newsom said there would be a debate with the Florida governor, perhaps in November, although the camps are still working out the details.

“I get to do the one thing I look forward to doing more than anything else, and that’s make the case for Joe Biden and what he’s accomplished — and to do that one on one,” he said of a DeSantis debate. “That’s an opportunity, a platform I don’t want to walk away from.”

Meanwhile, in a show of confidence, the Trump campaign has already begun to pivot toward a general election matchup against Mr. Biden.

His team says he currently plans to skip all Republican presidential debates, sensing few consequences for skipping the first one last month. Mr. DeSantis, once thought to be a potent threat, has struggled to live up to expectations.

Mr. Trump’s relationships across the party and his expansive political machine have made it extremely difficult for others to break through.

“The president benefits from having led the party for the last eight years,” said Trump’s political director, Brian Jack.

Mr. Trump is leading the fight for endorsements, winning the public backing of more members of Congress and statewide elected officials than the rest of the field combined.

The other candidates are also struggling to keep up with Mr. Trump’s quiet campaign to control the delegate selection rules for individual state primaries. Trump officials successfully pushed California Republicans to award all of the state’s 169 delegates to the winner of their March 5 primary, instead of doling out delegates to multiple candidates based on the proportion of their vote.

The payoff for that work became clear late last week when a pro-DeSantis super PAC scaled back its operations in Nevada and other states that host Republican primary contests in March, including California, North Carolina and Texas.

Given Mr. Trump’s overwhelming advantages, some of his powerful allies have begun to call for other Republican presidential candidates to give up. Miami’s mayor, Francis Suarez, ended his short-lived White House bid last week after failing to qualify for the opening debate. Yet at least eight high-profile opponents remain.

“It has been clear for months that President Trump will be the Republican nominee,” said Representative Elise Stefanik, the number 3 House Republican. “This election is the most important election in our lifetime, and I will continue to call on Republicans to coalesce our entire party apparatus behind President Trump’s campaign.”

While Mr. Trump remains the clear front-runner, he holds a wider margin nationally than he does in some of the early voting states. And influential Republicans there are aren’t ready to concede the nomination to Trump yet.

Governor Sununu of New Hampshire, which hosts the second Republican primary contest after Iowa, is working to boost Mr. Trump’s GOP rivals, warning that the former president is too flawed to win the general election.

Governor Branstad of Iowa, who served as Mr. Trump’s ambassador to China, also has doubts about the former president’s chances in the general election given the legal challenges that will play out for much of next year.

“The focus of the election ought to be on Biden and his record,” Mr. Branstad said. “That’s the thing that bothers me. It plays into the hands of the Democrats.”

He added, “I think this thing is going to tighten up.”

Even Mr. Trump isn’t quite willing to say that he’s already locked up the Republican presidential nomination.

“I don’t want to say anything’s over cause I don’t say that,” Mr. Trump said Friday on WABC. “I’m not a believer until it’s over, right? As Yogi would say, ‘Ain’t over ’til it’s over.”

Associated Press