Super Tuesday elections are being held in 16 states and one territory — from Alaska and California to Vermont and Virginia. Hundreds of delegates are at stake, the biggest haul for either party on any single day.

While much of the focus is on the presidential race, there are also important down-ballot contests. California voters will choose candidates who will compete to fill the Senate seat long held by Dianne Feinstein. The governor’s race will take shape in North Carolina, a state that both parties are fiercely contesting ahead of November. And in Los Angeles, a progressive prosecutor is attempting to fend off an intense reelection challenge in a contest that could serve as a barometer of the politics of crime.

The spotlight, however, remains on the 81-year-old Biden and the 77-year-old Trump, who continue to dominate their parties despite both facing questions about their age and neither commanding broad popularity across the general electorate.

The earliest either can secure enough delegates to become his party’s presumptive nominee is March 12 for Trump and March 19 for Biden. But in a departure from most previous Super Tuesdays, both nominations are effectively settled, with Biden and Trump both looking ahead to a reprise of the 2020 general election.

“We have to beat Biden — he is the worst president in history,” Trump said Tuesday on the “Fox & Friends” cable morning show.

Biden countered with a pair of radio interviews aimed at shoring up his support among Black voters, who helped anchor his 2020 coalition.

“If we lose this election, you’re going to be back with Donald Trump,” Biden said on “DeDe in the Morning” hosted by DeDe McGuire. “The way he talks about, the way he acted, the way he has dealt with the African American community, I think, has been shameful.”

Despite Biden’s and Trump’s domination of their parties, polls make it clear that the broader electorate does not want this year’s general election to be identical to the 2020 race. A new AP-NORC Center for Public Affairs Research poll finds a majority of Americans don’t think either Biden or Trump has the necessary mental acuity for the job.

“Both of them failed, in my opinion, to unify this country,” said Brian Hadley, 66, of Raleigh, N.C.

The final days before Tuesday demonstrated the unique nature of this year’s campaign. Rather than barnstorming the states holding primaries, Biden and Trump held rival events last week along the U.S.-Mexico border, each seeking to gain an advantage in the increasingly fraught immigration debate.

A voter heads into the Central Methodist Church in Fayetteville, Ark., to cast their ballot Tuesday.

(Michael Woods / Associated Press)

After the Supreme Court ruled 9-0 on Monday to restore Trump to primary ballots following attempts to ban him for his role in helping spark the Jan. 6, 2021, Capitol riot, Trump pointed to the 91 criminal counts against him to accuse Biden of weaponizing the courts.

“Fight your fight yourself,” Trump said. “Don’t use prosecutors and judges to go after your opponent.”

Biden delivers the State of the Union address Thursday, then will campaign in the key swing states of Pennsylvania and Georgia.

The president will defend policies responsible for “record job creation, the strongest economy in the world, increased wages and household wealth, and lower prescription drug and energy costs,” White House communications director Ben LaBolt said in a statement. LaBolt also drew a contrast to Trump’s priorities that he described as “rewarding billionaires and corporations with tax breaks, taking away rights and freedoms, and undermining our democracy.”

Biden’s campaign called attention to Trump’s most provocative statements that evoked Adolf Hitler by declaring that immigrants are “poisoning the blood” of the U.S. and suggesting flippantly that he would act as a dictator on his first day back in the White House.

Trump recently told a gala for Black conservatives that he believed African Americans empathized with his four criminal indictments. That drew another rebuke from Democrats around the country for comparing personal legal struggles to the historical injustices Black people have faced in the U.S.

The former president has nonetheless already vanquished more than a dozen major Republican challengers and now has only one left: Nikki Haley, the former president’s onetime U.N. ambassador who was also twice elected governor of her home state of South Carolina.

Haley has hopscotched across the country, visiting at least one Super Tuesday state almost daily for more than a week suggesting Trump cannot defeat Biden. “We can do better than two 80-year-old candidates for president,” Haley said at a rally Monday in the Houston suburbs.

Haley has maintained strong fundraising and notched her first primary victory over the weekend in Washington, D.C., a Democrat-run city with few registered Republicans. Trump scoffed that Haley had been “crowned queen of the swamp.”

Trump’s victories nonetheless have shown vulnerabilities with influential voter blocs, especially in college towns like Hanover, N.H., home to Dartmouth College, or Ann Arbor, Mich., where the University of Michigan is located, as well as areas with high concentrations of independents. That includes Minnesota, a state Trump did not carry in his otherwise overwhelming Super Tuesday performance in 2016.

Seth De Penning, a self-described conservative-leaning independent, voted Tuesday morning in Eden Prairie, Minn., for Haley, he said, because the GOP “needs a course correction.” De Penning, 40, called his choice a vote of conscience and said he has never voted for Trump because of concerns about his temperament and character.

Still, Haley winning any Super Tuesday contests would take an upset, and a Trump sweep would only intensify pressure on her to leave the race.

Biden has his own problems, including low approval ratings and polls suggesting that many Americans, even a majority of Democrats, don’t want to see the 81-year-old running again. The president’s easy Michigan primary win last week was spoiled slightly by an “uncommitted” campaign organized by activists who disapprove of the president’s handling of Israel’s war in Gaza.

Organizers of the “uncommitted” vote are pushing similar protest votes elsewhere, including Minnesota. The state has a significant population of Muslims, including in its Somali American community. Gov. Tim Walz, a Biden ally, told the Associated Press last week that he expected some votes for “uncommitted” on Tuesday.

Biden is the oldest president ever and Republicans key on any verbal slip he makes. His aides insist that skeptical voters will come around once it is clear that either Trump or Biden will be elected again in November. Trump is now the same age Biden was during the 2020 campaign, and he has exacerbated questions about his own fitness with recent flubs, such as mistakenly suggesting he was running against Barack Obama, who left the White House in 2017.

“I would love to see the next generation move up and take leadership roles,” said Democrat Susan Steele, 71, who voted Tuesday for Biden in Portland, Maine.

Mary Veroneau, a 69-year-old old Maine Democrat, also voted for Biden but said “you’d honestly want a younger candidate” than either the president or the former president.

Such concerns haven’t moved ardent Trump supporters.

“Trump would eat him up,” Ken Ballos, a retired police officer who attended a weekend Trump rally in Virginia, adding that Biden “would look like a fool up there.”

Weissert reported from Washington and Barrow from Atlanta. Associated Press writers David Sharp in Portland, Maine.; Gary D. Robertson in Raleigh, N.C.; Sarah Rankin in Richmond, Va.; Trisha Ahmed in Eden Prairie, Minn., and Seung Min Kim in Washington contributed to this report.