Washington, DC – The political storm unleashed by last week’s presidential debate in the United States is still raging despite the White House’s assurances that President Joe Biden is not quitting the race.

The 81-year-old president’s disastrous performance against his predecessor Donald Trump has fuelled questions about his viability as a candidate, if not his fitness for office. During the debate, observers noted Biden regularly lost his train of thought and appeared exhausted or confused.

That has spurred pressure for Biden to drop out and make room for a different candidate to represent the Democratic Party, as the presidential election approaches in November.

Many of Biden’s potential replacements, however, have voiced support for him, but that has done little to quiet speculation about the president’s future.

Before the debate, Biden faced growing discontent among large segments of the Democratic base over his “ironclad” support for Israel’s war in Gaza, which has killed more than 38,000 Palestinians and sparked accusations of genocide.

So if a new Democratic candidate is nominated, repairing the fractures the war has caused in the party may be a top priority: Key demographics including young voters, progressives, Arabs and Muslims have all signalled discontent over the Gaza war.

Here, Al Jazeera looks at what Biden’s potential alternatives have said about the conflict.

Vice President Kamala Harris

Should Biden drop out, Harris would be the frontrunner to replace him at the top of the Democratic ticket.

A former senator representing California, Harris is the daughter of immigrants from India and Jamaica. She ran unsuccessfully for president in 2020.

As vice president, Harris represents the Biden administration, which has unflinchingly supported the war on Gaza. Still, she was one of the first senior administration officials to use the word “ceasefire” while calling for a truce in Gaza.

“Given the immense scale of suffering in Gaza, there must be an immediate ceasefire for at least the next six weeks,” Harris said in March.

Around that time, NBC News — citing anonymous officials — reported that Harris would have taken a more forceful stance against the war if given the chance by the White House.

“This is Biden’s war. This is Biden’s failure,” one source said. “I think she would have asked for a ceasefire a long time ago.”

Publicly, Harris has stressed that she is in complete alignment with Biden.

The vice president has been a fervent backer of Israel throughout her political career. In 2017, the first measure she co-sponsored as a senator was to condemn a United Nations Security Council resolution that denounced Israel’s illegal settlements in the occupied West Bank.

Later that year, she told the American Israel Public Affairs Committee (AIPAC) that she has a deep connection to Israel.

“Having grown up in the [San Francisco] Bay Area, I fondly remember those Jewish National Fund boxes that we would use to collect donations to plant trees for Israel,” Harris told an AIPAC conference.

Michigan Governor Gretchen Whitmer

Almost immediately after last week’s debate, commentators started floating the name of Whitmer as a possible replacement for Biden.

A popular politician from a key swing state, Whitmer gained national prominence in 2020 when she clashed with then-President Trump over COVID-19 pandemic policies. She cruised to re-election two years later.

As governor, Whitmer rarely deals with foreign policy. But she has voiced support for Israel on several occasions.

“We here in Michigan condemn this vile act of terrorism,” she said during an event at a synagogue days after Hamas’s October 7 attack in Israel. “We stand with Israel. And Israel has a right to defend itself.”

The gathering saw Michigan elected officials hold hands as they sang and danced in support of Israel — a gesture that many in the state’s large Arab community found offensive.

In recent months, Whitmer has also expressed sympathy for the loss of life in Gaza, but she declined to say whether the spiralling death toll among Palestinians would amount to a genocide.

“I am not going to weigh in where I know that a lot of these terms are used to inflame and divide us,” she told NBC News earlier this year.

In April, Whitmer was asked by CNN whether she supports a permanent ceasefire in Gaza; she skirted the question.

“I believe that the hostages need to be released and that the violence needs to stop, and we need to really talk about rebuilding Gaza and supporting the Palestinians,” she said.

While campaigning for governor in 2018, Whitmer said she “strongly” supports a Michigan law that penalises companies that boycott Israel.

California Governor Gavin Newsom

Since beating a recall effort in 2021, Newsom has been seen as a rising star in Democratic politics.

A vocal defender of the Biden agenda, the former San Francisco mayor has acted as a surrogate for the president’s campaign, making appearances in the media and at last week’s debate.

Like other US officials, Newsom strongly condemned the October 7 attack and travelled to Israel last year, where he expressed uncompromising support for the country.

“Despite the horror, what I saw and heard from the people of Israel was a profound sense of resilience. A commitment to community and common purpose, especially in these most difficult of times,” he said in a statement after his trip on October 20. “That’s the Israeli spirit. And it’s also the California spirit.”

Israel had killed nearly 4,400 Palestinians in Gaza by then — about four times the number of Israelis killed by Hamas on October 7.

In March, Newsom called for a ceasefire in Gaza in a letter addressed to California’s Muslim, Arab and Palestinian communities.

“I condemn the ongoing and horrific loss of innocent civilian life in Gaza,” he said at that time.

“I support President Biden’s call for an immediate ceasefire as part of a deal to secure desperately needed relief for Gazan civilians and the release of hostages. I also unequivocally denounce Hamas’s terrorist attack against Israel.”

Pennsylvania Governor Josh Shapiro

While he may not have the national name recognition that his fellow governors Newsom and Whitmer enjoy, Shapiro is considered one of the top candidates to potentially replace Biden.

The governor, who previously served as Pennsylvania’s attorney general, comfortably won his election in the Mid-Atlantic swing state in 2022. Since taking office, he has had positive approval ratings.

With regards to the war in Gaza, Shapiro has been a staunch supporter of Israel.

“The whataboutism used by some to justify Hamas’s unprovoked actions is ignorant and wrong,” he said last year. “There is no moral equivalency here. Israel has a right to defend itself.”

Shapiro has also been outspoken in denouncing what he describes as anti-Semitism by protesters who oppose the war in Gaza.

In April, he likened pro-Palestinian student protesters to the Ku Klux Klan. The campus protests, however, have been largely peaceful, and student leaders say accusations of anti-Semitism misrepresent their aim: to encourage their universities to divest from Israeli companies linked to the country’s human rights abuses.

“We have to query whether or not we would tolerate this if this were people dressed up in KKK outfits or KKK regalia making comments about people who are African American in our communities,” Shapiro told CNN.

Transportation Secretary Pete Buttigieg

Buttigieg mounted an unlikely presidential campaign in 2020 despite his thin resume, having only served as the mayor of a college town in Indiana. Nevertheless, he performed well in the early primaries before dropping out and endorsing Biden.

In 2021, he became the first openly gay cabinet secretary after the US Senate confirmed him to lead the Department of Transportation. But he has faced criticism over his response to several crises: There have been mass delays in civilian aviation, as well as a 2023 train derailment that caused a chemical spill in Ohio.

But liberal commentators describe him as an effective communicator who can push back against Republican arguments.

In a rare comment on the Gaza conflict earlier this year, Buttigieg suggested that he understands why many people voted “uncommitted” in the Michigan Democratic primaries to protest Biden’s support for the war.

“First of all, I get it, and nobody can look at what is happening there and feel good,” he told the Pod Save America podcast in February.

“The other thing I’ll say is that, right now, negotiations are under way to make sure that two things happen: an end to the killing and the return of the hostages.”

During his presidential run, Buttigieg expressed support for Israel.

In 2019, he also said the US should not “foot the bill” for the possible annexation of the occupied West Bank by Israel.

But months later, he appeared to change his position. Asked whether he would pledge to place conditions on aid to Israel to prevent annexation, he said: “If you’re asking me to commit to withdrawing American support for Israel, the answer is no.”