Kamala Harris will begin a US tour with her new running mate next week, indicating that she may unveil her choice by Monday.
The pool of candidates for Democratic vice-president has been narrowed to a group of five, according to sources.
A decision is required before the Democratic National Convention, which starts on 19 August in Chicago. The presidential election is in November.
Once Ms Harris’s running mate is announced, the two are expected to tour the battleground states.
This charismatic and popular governor could help Ms Harris capture Pennsylvania – a must-win for Democrats.
Mr Shapiro, 51, has seen high approval ratings since he was elected in 2022 and has made inroads for Democrats in a swing state that went to Trump in the 2016 election.
He captured national headlines after quickly working to rebuild a collapsed bridge on a pivotal Philadelphia highway last year. The speedy repair was hailed by many as the perfect infrastructure talking point for a potential 2028 presidential candidate.
He would be the first Jewish vice-president if chosen by Ms Harris and the Democratic ticket proves victorious.
Mr Shapiro voiced strong support for Israel in the war in Gaza and his criticism of student protests on school campuses in his state could be divisive in the Democratic party and the race for office.
Vulnerabilities: Public education advocates have pointed to Mr Shapiro’s support of private school vouchers in Pennsylvania – a Republican-backed proposal to send $100m to families for private school tuition and school supplies – as a potential weakness of Mr Shapiro’s.
In mid-July, a group of over two dozen pro-public school groups sent a letter to Ms Harris in which they urged her to pick another candidate who is “wholly committed to our nation’s public education system”.
The swing-state senator has an impressive resume that could appeal to voters on both sides of the aisle.
The former Navy combat pilot and Nasa astronaut has spent more than 50 days in space on multiple missions.
But Mr Kelly, 60, is newer to serving in Washington. He was sworn into office in December 2020.
His wife is Gabby Giffords, who was shot in the head 2011 in Arizona while serving in the House of Representatives.
Ms Giffords has since become one of the leading voices on gun safety laws, and the couple’s personal story could resonate with voters.
Mr Kelly’s strong border stance and occasional criticisms of the Biden administration could help appeal to independent and conservative voters.
If chosen, the party would need to fill his Senate vacancy in a key state.
Vulnerabilities: Mr Kelly has already come under some criticism for his role founding World View, a company specialised in high-altitude stratospheric balloons.
The firm received early venture capital funding from Chinese tech giant Tencent, although the company says it has “zero access, zero input and zero control” over it. Mr Kelly stepped away from the company in 2019, although he still has a financial stake in it through a blind trust.
Andy Beshear, Kentucky governor
The Democratic governor has been close to Ms Harris for a long time.
Mr Beshear, 46, has been able to carve out a successful career as a Democrat in a state that Donald Trump carried by 20 points in the last election. It is an appealing characteristic that could sweeten the Democratic ticket.
He has given a number of viral interviews criticising Donald Trump’s vice-presidential choice, JD Vance, and his opinions on the Appalachia region.
“He ain’t from here,” Mr Beshear has said of the freshman Ohio senator in interviews on CNN and MSNBC. He has called Mr Vance a “phony” and “fake” for his descriptions of the region and its residents in his book, Hillbilly Elegy.
“This is a guy that used to come a couple weeks a summer, at best, to Kentucky and then wrote a book claiming to know us, claiming to understand our culture,” Mr Beshear told the Des Moines Register.
“He called my people lazy, and these are the coal miners that built this country.”
Mr Beshear often professes his Christian faith and its impact on his personality and work. Supporting public education and protecting abortion access are also key issues for him.
Vulnerabilities: In 2023, Mr Beshear drew the ire of some Kentucky Republicans for his veto of a law that banned transgender surgery or drugs involving children. The state’s general assembly ultimately overrode his veto and enacted the law.
Tim Walz, Minnesota governor
Mr Walz is a battle-tested leader who served 12 years in Congress before becoming governor in 2018.
He has gained national attention for his strategy calling Donald Trump and JD Vance “weird”.
The phrase caught on with a number of Democrats – including Ms Harris. “He’s just a strange, weird dude,” Mr Walz said of Trump during a fundraising event on Monday.
His plainspoken and small-town Midwestern persona could appeal to independent and conservative voters.
The 60-year-old led Minnesota through the 2020 protests over George Floyd’s death in Minneapolis
He deployed the National Guard to help quell riots that broke out during the demonstrations.
Mr Walz served 20 years in the National Guard, taught high school and also worked as an assistant football coach.
Minnesota is arguably less of a swing state, but would be a valuable asset for Ms Harris.
Vulnerabilities: Mr Walz’s political foes have criticised his handling of the Covid-19 pandemic and the 2020 protests, with Minnesota GOP chairman David Hann recently telling Fox that he believes Mr Walz “was fearful of alienating his progressive base” with a more forceful response.
Pete Buttigieg, Transportation Secretary
Campaigning for the White House would not be new for Mr Buttigieg.
As mayor of South Bend, Indiana, he was a surprise favourite of liberal voters in his failed 2020 Democratic primary campaign.
Since then, he has served as federal Transportation Secretary and has become arguably one of the White House’s best communicators.
His skill in interviews and before crowds has been on full display in recent weeks as Ms Harris closes in on a running mate.
On the television show Real Time with Bill Maher, he took multiple shots at Mr Vance. Mr Buttigieg said he “knows” a lot of people like Mr Vance, who “would say whatever they needed to” in order to get ahead.
Mr Buttigieg, 42, pointed out Mr Vance’s history of fiercely criticising Trump and how he’s now changed his tune to “get power”.
He also managed a number of public crises in his role as secretary, helping to oversee the response to the East Palestine train derailment in Ohio, the Baltimore Bridge collapse and Southwest Airlines’ scheduling crisis in 2022.
Vulnerabilities: Some Republicans have criticised Mr Buttigieg for his handling of his role as transportation secretary, saying he took too long to go to East Palestine and has been ineffective when addressing problems facing the US aviation sector.
Conservatives also assailed Mr Buttigieg in 2021 for taking two months’ parental leave during a supply-chain crisis.
