US election: Who can replace Joe Biden as lead candidate?

The first 2024 presidential debate between Donald Trump and Joe Biden proved disastrous for the current US president. Biden, who is now 81, often appeared confused, slurring and stumbling over his words, making 78-year-old Trump, famous for his emotionally fueled, hard-to-follow rants, look collected and lucid by comparison.

Both voters and the Democratic Party have taken notice. Despite party leaders closing ranks behind Biden, and the White House insisting that he was  "absolutely not" dropping out of the race, speculation is rife about other potential candidates to stand against Trump this November. So, who could take over Biden's campaign this late in the game?

Kamala Harris

Biden's second-in-command, Kamala Harris, is the most obvious choice for the next Democratic nominee. In 2020, she made history by becoming the first woman, the first Black person and the first person of Indian origin to serve as a US vice president.

But 59-year-old Harris has struggled to establish herself as a political leader independent from Biden during her time in the White House. In the early days of the Biden administration, she was tasked with leading the US response to mass immigration from Latin America. She has widely failed to curb migration and Trump's campaign has already used this against her.

Since 2023, Harris has been building up her profile as a voice for reproductive rights, even becoming the first vice president in history to visit an abortion clinic this March. Her gender identity and heritage might help her secure the support of more female, Black and Southeast Asian voters. At the same time, her career as a prosecutor in California leaves her open to attacks from parts of the left, best summarized under the "Kamala is a cop" slogan which haunted her presidential bid in 2019.

Harris has one more advantage over any other potential candidates: Seeing how she is already on the ticket with Biden, she could have legal access to the funds the two have raised for their campaign. Those funds currently amount to some $91 million (€84 million). Other politicians would have to solicit donors for funds, and a failure to raise enough money would put them at a disadvantage to the already established Trump campaign.

An Ipsos poll this week put Harris just one percentage point behind Trump (Harris' 42% to Trump's 43%) in a potential matchup. However, the same poll put Trump and Biden in a dead heat, with each of them projected to claim 40% of the votes.

Gretchen Whitmer

Michigan Governor Gretchen Whitmer is 52 and a legislative powerhouse within the Democratic Party. She has enacted a slew of progressive policies in her home state, including more tax credits for low-income families, more protection for LGBTQ+ groups, some gun control measures and securing funds to make Detroit-based car companies more environmentally friendly.

In 2020, she faced a plot by a right-wing group to kidnap her and put her on "trial" for alleged overreach regarding the COVID-19 lockdown measures in Michigan.

Just nine days after the plotters were arrested, Trump held a rally in Michigan, where he restated his criticism of Whitmer's pandemic policies, causing his supporters to chant "lock her up."

Whitmer is still popular in Michigan — a swing state — and is expected to run for president in 2028. Following the recent Trump-Biden debate, the news outlet Politico cited an unnamed source, claiming that Whitmer had complained Biden could no longer win in Michigan.

Whitmer dismissed this as false. "I am proud to support Joe Biden as our nominee and I am behind him 100% in the fight to defeat Donald Trump,” she said in a statement.

Gavin Newsom

California Governor Gavin Newsom was quick to defend Biden following the debate and dismiss calls that he should step down.

"You don't turn your back [on your candidate] because of one performance. What kind of party does that?" Newsom told the US television channel MSNBC.

However, while Newsom seems determined to ignore speculation about replacing Biden, he seems to find frequent mention as a likely contender in Biden's succession. The 56-year-old has a background in business and served as the mayor of San Francisco before being elected — then reelected — as the governor of California, America's most populous and richest state.

But Newsom's business ties and political career could be weaponized against him by the Trump campaign, especially over issues like widespread homelessness in the state and the surge of shoplifting in San Francisco.

JB Pritzker

Illinois Governor Jay Robert "JB" Pritzker was born into one of the world's richest families. The 59-year-old, heir to the Hyatt Hotels fortune, has a net worth of about $3.5 billion (€2.78 billion), as estimated by Forbes business magazine.

Pritzker has long used his fortune to support the Democratic Party and his own campaign bids. In 2008, he discussed his political ambitions in an intercepted call with the now-disgraced ex-governor of Illinois, Rod Blagojevich. Pritzker denies any wrongdoing in the matter.

The billionaire became governor of Illinois in 2018. He has since pushed for progressive policies on gun control, LGBTQ+ rights, reproductive rights, immigration, and minimum wage.

Pete Buttigieg

Current Secretary of Transportation Pete Buttigieg was a relatively unremarkable political figure before running for president in 2020 and subsequenty securing a place in Biden's administration. But his pre-politics career was all the more impressive: After graduating from Harvard, Buttigieg studied in Oxford, then worked for McKinsey consulting company. His eight-year career with the US Navy included six months in Afghanistan as an intelligence officer.

He became a mayor of South Bend, a small city in Indiana, in 2011, and launched a presidential bid in 2019, only to drop out of the race in favor of Biden. He has been one of the first openly gay candidates to run for president.

At 42, he is also by far the youngest candidate on this list.

Josh Shapiro

Pennsylvania Governor Josh Shapiro boasts large approval ratings in his state — which will be a crucial battleground against Trump in November. The 51-year-old is seen as a bipartisan leader, in favor of cutting corporate taxes, as well as hiring more police officers. During the height of the COVID-19 pandemic, Shapiro questioned some of the mask and vaccine mandates. Those stances could alienate voters from more liberal communities.

Shapiro, meanwhile, has accused US colleges for failing to address antisemitism at pro-Palestinian protests in the US. In May, he stated it was "past time" for the University of Pennsylvania to "disband the encampment" of student protesters. Previously, following a wave of similar student protests on US campuses, university students in Philadelphia had occupied college grounds to protest againt Israel's war in Gaza.

Following the Trump-Biden debate, Shapiro acknowledged that Biden "had a bad night" while noting Donald Trump had been "a bad president."

Michelle Obama

Former first lady Michelle Obama is the only candidate on this list who has never held political office — and the only one whom polls put far ahead of Trump should she choose to run.

This week's Ipsos poll projected her winning 50% of votes to Trump's 39%.

Michelle Obama has repeatedly said she has no interest in running for president. But if US politics have shown us anything in past weeks, it's that no outcome is too unlikely to be dismissed out of hand.

Edited by: Maren Sass