Could Kamala Harris be a winner for the Democrats if Biden steps aside?

Joe Biden’s stumbling debate performance left Democrats so panicked some are searching for an alternative to replace the 81-year-old president as the party’s standard-bearer.

Biden has given no indication that he intends to exit the race, and his campaign has flatly dismissed the suggestion. But that has done little to silence critics who are openly questioning whether Biden is the right person to take on Donald Trump, a figure the president – and his party – view as a grave threat to American democracy.

In the unlikely scenario Biden decides not to run, the most obvious choice to replace him would be his 59-year-old vice president and running mate, Kamala Harris. But it would not be automatic – and other candidates would likely challenge Harris, who has suffered her own low approval ratings, for the nomination.

Already some Democrats are looking past the vice-president at other possible contenders – Michigan governor Gretchen Whitmer, Illinois governor JB Pritzker, California governor Gavin Newsom and Maryland governor Wes Moore.

Related: Joe Biden bombed during the debate. But who will ask him to step down?

It’s a sign that Democrats have yet to fully embrace Harris as Biden’s heir apparent.

“To even discuss Biden stepping down while COMPLETELY IGNORING THE VP … is a serious look into how we see the importance, capacity and seriousness of women of color,” writer Tanzina Vega , said on X.

Harris, the daughter of Jamaican and Indian immigrants, is the highest-ranking female elected official in US history and the first Black and first Asian American to serve as vice president.

Democrats, traumatized by Hillary Clinton’s loss to Trump in 2016, rallied behind Biden in 2020 over a younger, more diverse and progressive field of candidates that included Harris. As a candidate, Biden promised to be a “ bridge ” to the next generation of Democratic leaders, which many interpreted as commitment to serve one-term and before passing the baton to Harris.

But when the time came to make a decision, Biden argued that he was still the Democrat best-positioned to beat Trump.

For the past three and a half years, Harris’s barrier-breaking vice-presidency has divided Democrats. Negative press, some of it self-inflicted, compounded by sexist and racist attacks, and a challenging policy portfolio weighed on public perception of the former California senator. Nearly 50% of voters have an unfavorable view of Harris, according to 538’s polling average , compared with the roughly 40% who view her favorably, figures that are comparable with Biden’s.

Despite a rocky start to her tenure, Harris has eased into the role, especially since becoming the administration’s leading voice on abortion rights. On Monday, Harris marked two years since the second anniversary of the US supreme court decision that overturned Roe v Wade with a fiery warning that Trump would not hesitate to further restrict women’s reproductive rights in a second-term.

Nodding to her background as a prosecutor, the vice president declared: “In the case of the stealing of reproductive freedom from the women of America, Donald Trump is guilty.”

Harris’s clear defense of abortion rights, by far Democrats’ strongest issue, stands in stark contrast to Biden. During Thursday’s debate, Biden fumbled an attack on Trump over Republican bans on the procedure, pivoting bizarrely to immigration and raising the case of a young woman murdered in Georgia.

Moments after Biden finished the debate, it was Harris who came to his defense first in a pair of interviews. On CNN and MSNBC, Harris spun his performance, saying voters must look at the last three-and-a-half years of accomplishments and not just at the 90-minute debate. Harris conceded that Biden had a “slow start” but insisted he finished “strong.”

“I’m talking about the choice for November,” she said on CNN. “I’m talking about one of the most important elections in our collective lifetime.”

In a sharp back-and-forth, CNN anchor Anderson Cooper pressed Harris about calls for Biden to step aside.

“I’m not going to spend all night with you talking about the last 90 minutes when I’ve been watching the last three-and-a-half years of performance,” she said, emphasizing his legislative and executive achievements he’s pulled in his first-term.

At a rally in Las Vegas the following day, Harris doubled down on her support.

“In the Oval Office, negotiating bipartisan deals, I see him in the situation room keeping our country safe,” she said, adding that the election would not be decided by “one night in June”.

The Atlanta debate was the first of the election cycle, with a second scheduled in September. The Biden campaign has agreed to a vice-presidential debate between Harris and Trump’s eventual running mate, but the terms have not yet been to confirmed.

In a hypothetical matchup against Trump, Harris performed roughly on par with Biden, trailing the former president by six points in a February Times/Siena poll . Biden trailed Trump by five points in the same poll. Meanwhile, the poll found Harris ran stronger than Biden with Black voters, though worse with Hispanic voters and men.

Biden’s age has long been an electoral challenge. But his shaky debate performance shocked even his staunchest supporters. At a rally on Friday, Biden acknowledged his stumbles, but insisted he was still the best candidate to defeat Trump.

“I know I’m not a young man, to state the obvious,” he said at a post-debate rally in North Carolina. “I know I don’t walk as easy as I used to, I don’t speak as smoothly as I used to, I don’t debate as well as I used to, but I know what I do know. I know how to tell the truth.”

But mounting concerns about Biden’s mental acuity have drawn even greater scrutiny of Harris, particularly from the right. Republicans have sought to make Harris a boogyman, with Nikki Haley warning during the GOP primary a vote for Biden was a vote for “a President Harris”.

With the convention scheduled for mid-August in Chicago, and the formal nomination process to take place virtually at some point before that to meet an Ohio ballot deadline, many Democrats have said there is not enough time to replace Biden at the top of the ticket.

Former South Carolina lawmaker and Democratic commentator Bakari Sellers, who endorsed Harris in the 2020 primary, said wishing for an alternative to emerge at this stage was futile.

“You’re not nominating Gretch or Gavin or Wes over Kamala. Stop it,” he wrote on X, adding: “Choice is Trump, Biden or couch. I choose Joe.”