Democrats have a ready-made replacement if Joe Biden stands aside before November’s election.

She’s been vetted. Her election would be historic. And she would easily take up the Biden mantle.

One issue stands out: Kamala Harris is currently the most unpopular vice president in American history and is considered one of the least probable candidates to defeat Donald Trump in a general election.

But Democrats may be stuck with her anyway.

Former Democratic National Committee chairwoman Donna Brazile explained the party’s challenge most succinctly.

‘How the f*** are you going to put all these white people ahead of Kamala?’ she said last week.

Despite this, Harris’s left-leaning supporters are lining up to endorse her as the next Democratic leader, despite there being other more competent candidates such as California Governor Gavin Newsom and Michigan’s Gretchen Whitmer.

On Tuesday, former Democratic Ohio Congressman Tim Ryan called it ‘utterly preposterous’ and ‘insulting’ to deny that Harris the chance to succeed Biden.

Hours later, South Carolina Rep. James E. Clyburn, at one time the second-highest ranking Democrat in the House, said he would also back Harris if Biden quits.

That has many in the Democrat donor class, left-wing pundits and even party faithful feeling hopeless.

Now, an exclusive new DailyMail.com poll can back up the handwringing with hard data. 

For according to a survey of 1,000 likely voters, conducted in the days following Biden’s catastrophic CNN debate performance last Thursday, Harris would lose to Donald Trump by 11 percentage points in a hypothetical election head-to-head – 38 to 49 percent.

Biden, despite struggling for 90 minutes to form complete sentences on live TV, only trailed Trump by five points in a head-to-head matchup – 42 to 47 percent.

Former First Lady Michelle Obama also outperformed Harris – coming up short against Trump by five points.

All other names floated as possible Biden replacements – Whitmer, Newsom, Transportation Secretary Peter Buttigieg – lose to Trump by double digits. 

But, while undoubtedly unlikeable, those Democrats are not as well-known to the public as Harris and, therefore, would likely find it easier to reform their images.

‘Kamala Harris has a high name ID, which means her brand is harder to change,’ said pollster James Johnson, who conducted the Mail survey. ‘Unlike other candidates who are a blank slate to voters and can more easily define themselves, Harris brings a lot of baggage.’

When the Mail’s poll respondents were asked to sum up the vice president in a word the most common response was ‘incompetent.’

In a sign of support from Democrats, the second most common word was ‘competent’ – which is hardly effusive praise – followed by ‘strong’, ‘stupid’, ‘corrupt’, ‘horrible’, and ‘dumb’.

In public, Harris has developed a reputation for delivering heaped helpings of ‘word salad’ – a phrase to describe her rambling explanations of seemingly simple concepts.

During a visit to a children’s hospital in May, Harris said: ‘We all believe that when we talk about the children of the community, they are children of the community.’

A comedian on Democrat-friendly ‘The Daily Show’ lampooned her distinctive style as ‘speaking without thinking’.

Early on in the Biden administration, the president tasked Harris with addressing the burgeoning illegal immigration crisis.

Three months later, when pressed by NBC News’s Lester Holt on why she hadn’t even visited the southern border, Harris strangely insisted that she had.

‘We’ve been to the border,’ she claimed.

‘You haven’t been to the border,’ Holt replied.

‘And I haven’t been to Europe,’ Harris shot back with an awkward laugh. ‘I mean, I don’t understand the point that you’re making.’

For the next year, Harris avoided sit-down interviews. And even Biden described his VP as a ‘work in progress.’

Whitney Tilson, a major Democratic fundraiser and former hedge fund manager, said this week that Harris is ‘among the least likely to beat Trump, based on my polls, lots of feedback from friends and readers, and my own observations.’

In one painfully revealing moment inside the liberal enclave of MSNBC’s ‘Morning Joe’ on Tuesday, host Mika Brzezinski let out an audible sigh as her interviewee explained how Harris could become the Democrat’s standard bearer.

‘That was me. That was all me,’ she admitted.

Meanwhile, Democratic strategist Hank Sheinkopf conceded that selling Harris to the American public as their next commander-in-chief would be difficult.

‘She’s going to have to make herself believable as a world leader. That’s very tough,’ Sheinkopf told the Mail.

Harris’s 2020 presidential primary run was a near-unmitigated disaster.

She dropped out before the first contest after failing to gain any traction with the electorate – but not before confronting Biden on the debate stage over his record on racial issues.

She attacked him for his one-time opposition to busing minority school children to majority-white schools.

‘There was a little girl in California who was part of the second class to integrate her public schools and she was bused to school every day,’ Harris said, ‘That little girl was me.’

Jill Biden reportedly blew up in anger over the affront during a phone call with supporters, saying, ‘You get up there and call him a racist without basis? Go f*** yourself.’

Despite Jill’s outrage and Harris’s political ineptitude, Biden ended up tapping her to be his vice president amid pressure from the party’s identity-obsessed progressive wing, who demanded he put a black woman on the Democratic ticket.

What’s more, Biden suggested he’d serve one term only – and that Kamala would be next to lead the party.

‘I view myself as a bridge [president], not as anything else,’ the then-78-year-old candidate assured a Detroit rally crowd in March 2020, after concerns were raised over his age. ‘There’s an entire generation of leaders you saw stand behind me. They are the future of this country.’

Those comments have no doubt come back to haunt him. 

‘Biden can’t now say that he’s stepping down and not pass the torch to Kamala,’ Republican strategist Scott Jennings told the Mail. ‘To do that would be to admit she was never qualified in the first place.’

And that’s not the only hurdle for anti-Harris Democrats.

In a call with party donors on Sunday, Biden campaign manager Julie Chávez Rodriguez explained that only Harris would be eligible to spend the $91.2 million raised by the campaign.

Under Federal Election Commission rules, the cash is not transferable to another candidate.

That means if someone other than Harris becomes the nominee, the money haul must be returned to donors. They could then decide if they wanted to back the new candidate.

Ironically, DailyMail.com’s reporter Charlie Spiering wrote in his book, ‘Amateur Hour: Kamala Harris in the White House’, that Biden is only running for a second term, because of his lack of faith in his vice president to beat Donald Trump.

Now, he may not have any say in the matter.