US elections | Who could replace Joe Biden as the 2024 Democratic nominee?

President Joe Biden's decision to step down as the Democratic Party's nominee for president opens the door for other contenders to become the Democratic nominee in November.

The president has thrown his support behind Vice President Kamala Harris, and other prominent Democrats moved quickly to rally around her candidacy, but it's unclear just how smooth her path to the party's nomination is.

Here are some of the leading contenders for a spot on the Democratic ticket:

Vice President Kamala Harris

Born in Oakland, California, Vice President Kamala Harris calls Thurgood Marshall an inspiration and talks often about growing up with parents deeply involved in the civil rights movement.

Her economist father and cancer specialist mother met as graduate students at the University of California, Berkeley, where Harris recalled they spent ample time "marching and shouting about this thing called justice.”

In choosing Harris as his running mate in 2020, Biden called her a “fearless fighter for the little guy.” She has not wavered as his vice-presidential nominee and has become more visible campaigning for the Biden-Harris ticket in recent weeks.

Harris, who is Black and also of South Asian descent, is the nation's first female vice president and the first person of colour to hold that office. A graduate of Howard University, she also is the first person from a historically-Black college or university to hold the office of either president or vice president.

Harris won her seat in the U.S. Senate in 2016 after twice being elected California attorney general. As a Senate candidate, she stressed her fights with big banks during the mortgage crisis, for-profit colleges that were financially exploiting students, and environmental wrongdoers.

She's talked for years about recidivism and criminal justice reform, and pushed for a different approach to non-violent crimes that emphasises rehabilitation instead of severe, one-size-fits-all punishment. She calls it being “smart on crime”.

As vice president, Harris has been asked by Biden to take on some of the most challenging tasks his administration has faced, including securing the nation's borders. As the presiding officer of the US Senate, she has cast a record number of tie-breaking votes on legislation promoted by Democrats, who are defending a razor-thin majority in both houses of Congress in this year's elections.

Harris, 59, is married to Los Angeles lawyer Douglas Emhoff.

Illinois Governor JB Pritzker

Illinois Gov. JB Pritzker, the richest politician holding office in the US, is an heir to the Hyatt Hotel fortune, a former private equity investor and philanthropist. His net worth of $3.4 billion puts him at No. 250 on the Forbes 400 list of the richest Americans.

The 59-year-old Pritzker won the nomination for governor in 2018, besting a crowded Democratic field. He beat one-term incumbent Republican Gov. Bruce Rauner and inherited mountains of state debt, unpaid bills, and ratings by Wall Street credit houses just above junk status because of Rauner's two-year feud with legislative Democrats that resulted in the state going without a budget plan.

Working with Democratic supermajorities in the House and Senate, Pritzker has boasted balanced budgets and paid down billions of dollars in debt, prompting multiple credit upgrades. He also has overseen increased education funding, the centralisation of early childhood services, and new laws to make health insurance more comprehensive, accessible, and affordable.

He became the first Illinois governor to be elected to a second term in 16 years. He then promptly delivered a victory speech that sounded like it came from a national candidate, denouncing Trump and asking, “Are you ready to fight?”

Michigan Governor Gretchen Whitmer

Michigan Gov. Gretchen Whitmer has rapidly risen in prominence within the Democratic Party since first winning the 2018 gubernatorial election after serving for a decade and a half in the state legislature.

Her national profile grew significantly during the final years of Donald Trump's presidency when she emerged as one of the Democratic Party's most effective voices opposing the then-president. She delivered the Democratic response to Trump's 2020 State of the Union address and frequently clashed with him over how the federal government handled the COVID-19 pandemic.

In her 2022 reelection campaign, Whitmer focused on reproductive rights, resulting in a double-digit victory and passage of a voter-approved measure codifying abortion rights in the state. The massive Democratic victories in a swing state that Trump won in the 2016 presidential election positioned Whitmer as a leading advocate for reproductive freedom and a strong contender for a future presidential nomination.

The 52-year-old Democrat has been working to boost her national profile. She met with Biden in 2020 as he considered who to select as a running mate and she is currently on a national press tour for her new memoir. Whitmer has also set up a national political action committee that has raised millions this election cycle.

California Governor Gavin Newsom

California Gov. Gavin Newsom is a native of San Francisco who got involved in politics by volunteering for Willie Brown's 1995 campaign for mayor. Two years later, Mayor Brown appointed Newsom to a vacant seat on the San Francisco Board of Supervisors, where he was later elected and reelected.

Newsom then became mayor himself and received national attention in 2004 when he directed the San Francisco clerk to issue marriage licenses to same-sex couples.

He was elected lieutenant governor in 2010 and unapologetically pushed a progressive agenda when he successfully ran for governor eight years later. Now in his second term, he says he is “standing up for California values - from civil rights to immigration, environmental protection, access to quality schools at all levels, and justice,” according to his official bio.

Newsom, 56, has maintained a high national profile this year, challenging Republican presidential candidates in public appearances despite not being a candidate himself. The governor was a baseball star at Santa Clara University. After graduating, he worked briefly in sales before starting a retail wine shop that grew into the PlumpJack Group, which includes restaurants, resorts, and vineyards throughout California.

He is married to Jennifer Siebel Newsom. They have four children.

Pennsylvania Governor Josh Shapiro

Pennsylvania Gov. Josh Shapiro, long seen as a rising political star in Pennsylvania, is halfway through his second year as governor after easily winning his last election by trouncing a far-right, Donald Trump-endorsed candidate. Shapiro, 51, has been a surrogate for Biden, backing the president in appearances on cable networks, and has years of experience making former President Trump the focus of his attacks, first as state attorney general and now as governor.

If he joins a Democratic ticket, Shapiro would become the first presidential nominee of Jewish heritage or the second vice-presidential nominee of that background, after former Democratic Sen. Joe Lieberman of Connecticut in 2000.

Shapiro has won three statewide races - two as attorney general, one as governor - with a tightly-scripted, disciplined campaign style, offering voters something of a lower-key alternative to the state's brash political star, US Sen. John Fetterman.

Shapiro has aggressively confronted what he viewed as anti-semitism cropping up from pro-Palestinian demonstrations, and has professed solidarity with Israel in its drive to eliminate Hamas. He is a staunch proponent of abortion rights in Pennsylvania and routinely touts his victories in court against Trump, including beating back challenges to the 2020 election results.

North Carolina Governor Roy Cooper

North Carolina Gov. Roy Cooper has won six statewide general elections over two decades in a state where Republicans routinely prevail in similar federal races and also control the legislature.

Cooper, 67, has received strong job-approval ratings as governor, benefitting from a booming state economy, for which his administration and lawmakers take credit. He also portrays himself as a fighter for public education and abortion rights.

He obtained both his undergraduate and law degrees from the University of North Carolina. He upset the Democratic incumbent in a 1986 state House primary race and was elected to the General Assembly. He served 14 years there and later became the Senate majority leader.

Cooper was elected attorney general in 2000, a position he held for 16 years. He unseated another incumbent in 2016, this time Republican Gov. Pat McCrory by roughly 10,000 votes. His time as governor was marked by restricting business and school activity during the COVID-19 pandemic. He won reelection in 2020 by 4.5 percentage points, even as Donald Trump won the state's electoral votes.

Cooper and his wife, Kristin, have three grown daughters.

Kentucky Governor Andy Beshear

Kentucky Gov. Andy Beshear secured his reputation as a rising Democratic star by beating Trump-endorsed Republicans in his bright red state.

He displayed a disciplined, tenacious style in winning reelection last year, defeating then-Attorney General Daniel Cameron. The governor has urged Democrats to follow his winning formula by focusing on the everyday concerns of Americans, from good-paying jobs to quality education and health care.

The governor won widespread praise for his empathy and attention to detail in guiding the Bluegrass State through the COVID-19 pandemic and leading the response to tornadoes and flooding that caused massive damage. He has presided over record-setting economic growth in Kentucky, and he typically begins his briefings by touting the state's latest economic wins. He frequently mentions his Christian faith and how it guides his policymaking.

An attorney by trade, Beshear won election as state attorney general in 2015. He then unseated Trump-backed Republican incumbent Matt Bevin to first win the governorship in 2019. Beshear entered politics with a strong pedigree as the son of former two-term Gov. Steve Beshear, but the son has faced tougher political obstacles.

Senator Mark Kelly

US Senator Mark Kelly of Arizona leveraged his career as an astronaut to build a brand as a moderate in a state that long supported Republicans.

In his two campaigns, Kelly has earned more votes than any other Democrat on the ballot. He outpolled Biden, who narrowly won Arizona by 2 percentage points in 2020.

Kelly's first turn in the national political spotlight came through tragedy. His wife, then-US Rep. Gabrielle Giffords, was shot in the head while meeting with constituents outside a grocery store in Tucson, a shooting that left six people dead and spawned an early reckoning with political violence and partisan rancour.

Giffords' improbable survival made her a national inspiration but snuffed out a promising political career of her own. She and Kelly went on to found a gun-control advocacy group, and Giffords has been a powerful surrogate as Kelly has taken her place in politics.

In the Senate, Kelly has focused on national security and the military as well as the drought plaguing the US West. He was a Navy test pilot and flew 39 combat missions during the Gulf War before joining NASA, where he flew three missions on the space shuttle.

Originally from New Jersey, he settled with Giffords in Tucson after retiring from NASA and the Navy.

(With agency inputs)