WASHINGTON -- The 2024 presidential race is taking shape, with former President Donald Trump mounting a comeback bid for the White House, facing GOP competition from Florida Gov. Ron Desantis, former South Carolina Gov. Nikki Haley, former Arkansas Gov. Asa Hutchinson, South Carolina Sen. Tim Scott and others.
President Joe Biden will also run for reelection.
Here's an updated list of who is running for president in 2024 and a brief look at politicians who have definitively ruled out a campaign.
President Joe Biden, Democrat
President Joe Biden on April 25 formally announced that he is running for reelection in 2024, asking voters to give him more time to "finish this job" he began when he was sworn into office and to set aside their concerns about extending the run of America's oldest president for another four years.
Biden, who would be 86 at the end of a second term, is betting his first-term legislative achievements and more than 50 years of experience in Washington will count for more than concerns over his age.
"[My] intention has been from the beginning to run. But there's too many other things we have to finish in the near term before I start a campaign," he told ABC News anchor David Muir at the White House in February.
Biden told Muir in December 2021 that the possibility of a rematch with Trump wouldn't dissuade him.
"Why would I not run against Donald Trump for the nominee? That'll increase the prospect of running," he said.
Trump, 76, formally launched his third bid for the White House on Nov. 15, following the 2022 midterms, which did not meet Republican expectations.
Trump announced his campaign from his Mar-a-Lago estate in Palm Beach, Florida. It didn't come as a surprise, given that Trump had been hinting for months that he would make a run.
"America's comeback starts right now," he said, describing the U.S. as "in decline" and touting his administration as a "golden age."
However, Trump's third run for the White House comes as he faces an indictment in New York, a federal indictment into his handling of classified documents after leaving office -- both of which he has pleaded not guilty to.
He also faces investigations into the alleged efforts to overturn his 2020 loss in Georgia and the events leading up to the attack on the capitol on Jan. 6 -- which he has denies wrongdoing.
He's also become increasingly estranged from some other leading figures in the GOP in the wake of Jan. 6, his 2020 election lies and other controversies and scandals.
While polling shows he remains popular with many voters in the party, many others say they want another nominee.
"America's comeback starts right now," he insisted in his announcement speech.
Ron DeSantis, Republican
Florida Governor Ron DeSantis entered the 2024 Republican presidential primary race on May 24 -- setting the stage for a long awaited and potentially volatile contest between the Florida governor, who is a rising star in his party, and former President Donald Trump, who has so far dominated most polls in the very early months of the election.
DeSantis, 44, was reelected to second term by a near 20-point margin in November. He will enter the GOP primary field as Trump's biggest rival, according to observers and voter surveys.
A recent ABC News/Washington Post survey showed that among the six best-known candidates, Trump clinched 51% of Republicans and GOP-leaning independents while DeSantis garnered 25%. A majority of those voters said they'd be satisfied with either Trump (75%) or DeSantis (64%) as their presidential nominee.
Mike Pence, Republican
Former Vice President Mike Pence opened his bid for the Republican nomination for president June 6 with a firm denunciation of former President Donald Trump, accusing his two-time running mate of abandoning conservative principles and being guilty of dereliction of duty on Jan. 6, 2021.
Pence, launching his campaign in a suburb of Des Moines, became the first vice president in modern history to challenge the president under whom he served. He said Trump had disqualified himself when he insisted that Pence had the power to keep him in office - even though he did not.
Trump, he said, "endangered my family and everyone at the Capitol" on the 6th. "But the American people deserve to know that on that day, President Trump also demanded I choose between him and our Constitution. Now voters will be faced with the same choice."
Nikki Haley, Republican
Haley, 51, announced her presidential bid in a video released on Feb. 14, a day ahead of a formal kickoff on Feb. 15 in Charleston.
Haley, who also served as a U.S. ambassador to the U.N. in the Trump administration, is the first high-profile Republican to challenge Trump.
In her announcement video, Haley, the daughter of immigrants, highlighted her heritage as a South Asian woman and touted her hopeful view of what America can offer.
"My mom would always say, 'Your job is not to focus on the differences but the similarities.' My parents reminded me and my siblings every day how blessed we were to live in America," Haley said.
She underscored her credentials as a former leader of the Palmetto State, stressing its resilience, but most of all she said there was major need for change in the GOP's candidates.
"Republicans have lost the popular vote in seven of the last eight presidential elections. ... It's time for a new generation of leadership," she said.
Haley was elected as the first female governor of South Carolina in 2010, stepping down in 2017, during her second term, to serve as a Trump ambassador until 2018.
Chris Christie, Republican
Republican former New Jersey Gov. Chris Christie kicked off his presidential campaign June 6, promising to be the only candidate in a crowded GOP primary field willing to directly take on former President Donald Trump.
"Donald Trump made us smaller by dividing us even further and pitting us one against the other," Christie said, suggesting that the former president was part of a broader political effort to "paint all Republicans with just one brush."
He added that President Joe Biden "is doing the same thing, just on the other side."
After losing the nomination to Trump in 2016, the former governor and federal prosecutor went on to become a close off-and-on adviser before breaking with the former president over his refusal to accept the results of the 2020 election.
Christie has become a fierce Trump critic in recent years and is now casting himself as the only Republican presidential candidate willing to openly pick fights with the former president - while also warning that the party failing to fully confront him will spark a repeat of the 2016 GOP primary, when Trump rolled over a host of alternatives with more political experience who split the support of voters opposing him.
Asa Hutchinson, Republican
Asa Hutchinson, who recently completed two terms as Arkansas governor, said he will seek the Republican presidential nomination on April 2, just days after the former president was indicted by a grand jury in New York.
Hutchinson said Trump should drop out of the race, arguing "the office is more important than any individual person."
Hutchinson,who announced his candidacy on ABC's "This Week," said he was running because "I believe that I am the right time for America, the right candidate for our country and its future." He added: "I'm convinced that people want leaders that appeal to the best of America and not simply appeal to our worst instincts."
Hutchinson, 72, left office in January after eight years as governor.
The former governor, who was term-limited, has been a fixture in Arkansas politics since the 1980s, when the state was predominantly Democratic. A former congressman, he was one of the House managers prosecuting the impeachment case against President Bill Clinton.
Hutchinson served as President George W. Bush's head of the Drug Enforcement Administration and was an undersecretary of the Department of Homeland Security.
As governor, Hutchinson championed a series of income tax cuts as the state's budget surpluses grew. He signed several abortion restrictions into law, including a ban on the procedure that took effect when the U.S. Supreme Court struck down Roe v. Wade last year. Hutchinson, however, has said he regretted that the measure did not include exceptions for rape or incest.
Tim Scott, Republican
Scott, 57, formally announced his candidacy on May 22 at his alma mater Charleston Southern University.
Scott, South Carolina's first Black senator and the Senate's sole Black Republican, shared an optimistic message of faith in the American dream as he launched his campaign.
"We live in the land where it is possible for a kid raised in poverty by a single mother in a small apartment to one day serve in the People's House and maybe even the White House," Scott said.
He joined the race with more cash on hand than all his Republican competitors, but was polling in the low single digits.
Steve Laffey, Republican
The former mayor of Cranston, Rhode Island, Steve Laffey announced his candidacy for president on Feb. 2.
In a statement, he said he wanted to confront the country's issues.
"Our country has done the equivalent of using Band-Aids in place of major surgery. Somehow, we have 'gotten by,'" he said. "For the first time in a generation, we must directly confront our problems."
Laffey is a long shot for the Oval Office, given his relative lack of name recognition or statewide or federal experience.
He previously made a run for Senate in 2006 in Rhode Island, against Republican Lincoln Chafee, who was ultimately defeated by Democrat Sheldon Whitehouse.
Vivek Ramaswamy, Republican
Entrepreneur Vivek Ramaswamy announced that he's running for the 2024 Republican presidential nomination on Feb.21.
"To put America first, we need to rediscover what America is. That's why I am running for president," Ramaswamy wrote in a Wall Street Journal editorial.
"I am launching not only a political campaign but a cultural movement to create a new American Dream-one that is not only about money but about the unapologetic pursuit of excellence."
Ramaswamy is a biotech and health care entrepreneur who has written two books, "Nation of Victims: Identity Politics, the Death of Merit, and the Path Back to Excellence" and "Woke, Inc.: Inside Corporate America's Social Justice Scam."
Perry Johnson, Republican
A 75-year-old Michigan businessman, Johnson launched his presidential campaign for the 2024 Republican nomination amid the 2023 Conservative Political Action Conference that began on March 1.
Johnson took third in CPAC's straw poll for presidential picks, with nearly 5% of the vote. While he polled behind Trump and Florida Gov. Ron DeSantis, he was ahead of Haley and others.
While Johnson has no experience in elected office, he has a long career in business in Michigan. with almost 30 years of experience in the quality standards field. Two of his companies -- Perry Johnson Registrars, and Perry Johnson, Inc. -- both can certify businesses as meeting certain industry standards.
Before CPAC, his most notable political bid was when he ran for governor in Michigan in 2022 but was removed from the ballot before the Republican primary due to what state officials found to be fraudulent and invalid petition signatures.
Larry Elder, Republican
Edler, 70, a conservative talk radio host, announced on April 20 that he was seeking the Republican nomination for president.
The long shot candidate first ran for elected office in 2021 in the recall election to replace California Democratic Gov. Gavin Newsom. Newsom survived the recall effort by a wide margin, but Elder placed first among the replacement candidates.
In a tweet, Elder said, "America is in decline, but this decline is not inevitable. We can enter a new American Golden Age, but we must choose a leader who can bring us there. That's why I'm running for president."
Doug Burgum, Republican
North Dakota Gov. Doug Burgum announced on June 7 that he is joining 2024 presidential race -- with a pitch to voters focused on lessons he learned out West.
Burgum, a former software CEO elected in 2016, teased his announcement with a video released on Monday. He's set to make it official during remarks from Fargo on Wednesday morning.
Burgum, 66, joins a long list of contenders hoping to dent former President Donald Trump's early lead in the race. The governor of the nation's fourth-least populous state kicked off his campaign in Fargo, near the tiny farm town of Arthur where he grew up.
Burgum founded Great Plains Software in 1983 and it was ultimately acquired by Microsoft in 2001; Burgum remained active in the company until 2007.
Burgum said he and the Legislature turned a budget deficit into a surplus, cut taxes and red tape, bolstered cybersecurity, and revitalized North Dakota's main streets. He also said they increased spending on education, strengthened tribal relations and boosted energy production.
He said his state is one of the very few that's growing and getting younger, with some of the lowest unemployment in the country.
Laws that Burgum signed this year include banning abortion with few exceptions up to six weeks' gestation and several restricting trans rights.
LGBTQ advocates demonstrated outside the hall. Cody Schuler, advocacy manager for the American Civil Liberties Union of North Dakota, pointed to Burgum's past reluctance to wade into culture war and gender expression issues.
Miami Mayor Francis Suarez
Miami Mayor Francis Suarez announced on Thursday morning he is running for president, challenging Donald Trump for the Republican nomination.
Suarez told co-anchor George Stephanopoulos in an exclusive interview on ABC's "Good Morning America" that he represents "generational change," but he repeatedly avoided answering about Trump's indictment or whether the former president had done anything wrong.
"This isn't about me. This isn't about my generation. This is about our children," Suarez said.
The 45-year-old mayor, the only Hispanic candidate in the race, declared his candidacy with the Federal Election Commission.
Suarez, the president of the U.S. Conference of Mayors, is the son of Miami's first Cuban-born mayor.
He has gained national attention in recent years for his efforts to lure companies to Miami, with an eye toward turning the city into a crypto hub and the next Silicon Valley.
Marianne Williamson, Democrat
Author Marianne Williamson formally announced that she's running for president in 2024 on March 4, her second bid for the White House following an unsuccessful campaign in 2020.
Her announcement set up the first -- albeit long-shot -- Democratic primary challenge to President Joe Biden, who has long said he intends to run for reelection but has yet to make a formal announcement.
"I have run for president before," she told supporters at her campaign launch at Union Station in Washington. "I'm not naive about the forces which have no intention of allowing anyone into this conversation who does not align with their predetermined agenda."
A Texas native who now lives in Beverly Hills, California, Williamson is the author of more than a dozen books and ran an unsuccessful independent congressional campaign in California in 2014.
In 2020, she was best known for wanting to create a Department of Peace and arguing the federal government should pay large financial reparations to Black Americans as atonement for centuries of slavery and discrimination.
Before running for office, the 70-year-old was best known as a onetime spiritual adviser to Oprah Winfrey.
Robert F. Kennedy Jr., Democrat
Democrat Robert F. Kennedy Jr., an anti-vaccine activist and scion of one of the country's most famous political families, filed a statement of candidacy April 5.
Kennedy, a nephew of President John F. Kennedy and the son of his slain brother Robert F. Kennedy, was once a bestselling author and environmental lawyer who worked on issues such as clean water.
But more than 15 years ago, he became fixated on a belief that vaccines are not safe. He emerged as one of the leading voices in the anti-vaccine movement, and his work has been described by public health experts and even members of his own family as misleading and dangerous.
Kennedy, 69, had been long involved in the anti-vaccine movement, but the effort intensified after the COVID-19 pandemic and development of the COVID-19 vaccine.
Kennedy released a book in 2021, "The Real Anthony Fauci," in which he accused the U.S.'s top infectious disease doctor of assisting in "a historic coup d'etat against Western democracy" and promoted unproven COVID-19 treatments such as ivermectin, which is meant to treat parasites, and the anti-malaria drug hydroxychloroquine.
Cornel West, Green Party
Philosopher and political activist Cornel West originally announced he was running for president for the People's Party, a left-wing populist political party, but soon after changed to run as the Green Party canidate.
Some of the issues West is running on include: Medicare for all, stopping all foreign military aid and disbanding NATO as well as enacting term limits and switching to hand-counted paper ballots.
West acknowledged in his campaign announcement video that his bid to the White House is a longshot.
"Do we have what it takes? We shall see but some of us are going to go down fighting, go down swinging with style and a smile," he said in his video.
Who isn't running
Maryland Gov. Larry Hogan on March 5 became the first major Republican mulling a presidential bid to say he will not run in 2024.
Hogan said in a statement that he would not "risk being part of another multicar pileup that could potentially help Mr. Trump recapture the nomination," as Trump did in 2016 when he won the GOP nomination amid a splintered field.
Former Secretary of State Mike Pompeo on April 14 became another high-profile Republican to announce he wouldn't be seeking the party's nomination.
"It is simplest, and most accurate, to say that this decision is personal," Pompeo said in a statement. "This is not the right time for me and my family."
"There remain many more opportunities for which the timing might be more fitting as presidential leadership becomes even more necessary," he continued.
And on June 5, New Hampshire Gov. Chris Sununu said he will not run -- in order to keep the field of Republican candidates less crowded so Trump is less likely to win.
"The stakes are too high for a crowded field to hand the nomination to a candidate who earns just 35 percent of the vote, and I will help ensure this does not happen," Sununu wrote in a column in The Washington Post.
The Associated Press and ABC News contributed to this report.