Nearly a month ago, Kamala Harris appeared on ABC's The View in what was expected to be a friendly interview aimed at pitching herself to Americans who wanted to know more about her.

But the sit-down was quickly overshadowed by her response to a question on what she would have done differently from incumbent president, Joe Biden: "Not a thing comes to mind."

Harris's answer - which became a Republican attack ad on loop - underscored the political headwinds that her jumpstart campaign failed to overcome in her decisive loss to Donald Trump on Tuesday.

Publicly, she conceded the race late on Wednesday afternoon, telling supporters "do not despair".

But soul-searching over where she went wrong and what else she could have done will likely take longer as Democrats begin finger-pointing and raising questions about the future of the party.

Harris campaign officials were silent in the early Wednesday hours while some aides expressed tearful shock over what they had expected to be a much closer race.

"Losing is unfathomably painful. It is hard," Harris campaign manager Jen O'Malley Dillon said in an email to staff on Wednesday. "This will take a long time to process."

As the sitting vice-president, Harris was unable to untether herself from an unpopular president and convince voters that she could offer the change they were seeking amid widespread economic anxiety.

After Biden dropped out of the race following a disastrous debate performance, Harris was anointed to the top of the ticket, bypassing the scrutiny of a primary without a single vote being cast.

She began her 100-day campaign promising a "new generation of leadership", rallying women around abortion rights and vowing to win back working-class voters by focusing on economic issues including rising costs and housing affordability.

With just three months until election day, she generated a wave of initial momentum, which included a flurry of memes on social media, a star-studded endorsement list that included Taylor Swift and a record-setting donation windfall. But Harris couldn't shake the anti-Biden sentiment that permeated much of the electorate.

The president's approval rating has consistently hovered in the low 40s throughout his four years in office, while some two-thirds of voters say they believe the US is on the wrong track.

Some allies have privately questioned whether Harris remained too loyal to Biden in her bid to replace him. But Jamal Simmons, the vice-president's former communication director, called it a "trap", arguing any distance would have only handed Republicans another attack line for being disloyal.

"You can't really run away from the president who chooses you," he said.

Harris tried to walk the fine line of addressing the administration's record without casting shade on her boss, showing a reluctance to break with any of Biden's policies while also not outwardly promoting them on the campaign trail.

But she then failed to deliver a convincing argument about why she should lead the country, and how she would handle economic frustrations as well as widespread concerns over immigration.

About 3 in 10 voters said their family's financial situation was falling behind, an increase from about 2 in 10 four years ago, according to data from AP VoteCast, a survey of more than 120,000 US voters conducted by NORC at the University of Chicago.

Nine in 10 voters were very or somewhat concerned about the price of groceries.

The same survey found that 4 in 10 voters said immigrants living in the US illegally should be deported to their country of origin, up from around 3 in 10 who said the same in 2020.

And though Harris tried to spend the home stretch of her campaign underlining that her administration would not be a continuation of Biden's, she failed to clearly outline her own policies, often skirting around issues instead of addressing perceived failures head on.

The Harris campaign had hoped to reassemble the voting base that powered Biden's 2020 victory, winning over the core Democratic constituencies of black, Latino and young voters as well as making further gains with college-educated suburban voters.

But she underperformed with these key voting blocs. She lost 13 points with Latino voters, two points with black voters, and six points with voters under 30, according to exit polls, which may change as votes are counted, but are considered representative of trends.

Independent Senator Bernie Sanders of Vermont, who lost the 2016 Democratic presidential primary to Hillary Clinton and the 2020 primary to Biden, said in a statement it was "no great surprise" that working class voters abandoned the party.

"First, it was the white working class, and now it is Latino and black workers as well. While the Democratic leadership defends the status quo, the American people are angry and want change," he said. "And they're right."

While women largely threw their support behind Harris over Trump, the vice-president's lead did not exceed the margins that her campaign had hoped her historic candidacy would turn out. And she was unable to deliver on her ambitions of winning over suburban Republican women, losing 53% of white women.

In the first presidential election since the Supreme Court overturned the constitutional right to abortion, Democrats had hoped her focus on the fight for reproductive rights would deliver a decisive victory.

While some 54% of female voters cast their ballots for Harris, it fell short of the 57% who backed Biden in 2020, according to exit poll data.

Even before she was catapulted to the top of the ticket, Harris had sought to frame the race as a referendum on Trump, not Biden.

The former California prosecutor leaned into her law enforcement record to prosecute the case against the former president.

But her nascent campaign opted to ditch Biden's core argument that Trump posed an existential threat to democracy, prioritising a forward-looking "joyful" message about protecting personal freedoms and preserving the middle class.

In the final stretch, however, Harris made a tactical decision to again highlight the dangers of a second Trump presidency, calling the president a "fascist" and campaigning with disaffected Republicans fed up with his rhetoric.

After Trump's former White House Chief of Staff, John Kelly, told the New York Times that Trump spoke approvingly about Adolf Hitler, Harris delivered remarks outside her official residence describing the president as "unhinged and unstable".

"Kamala Harris lost this election when she pivoted to focus almost exclusively on attacking Donald Trump," veteran Republican pollster Frank Luntz said on Tuesday night.

"Voters already know everything there is about Trump – but they still wanted to know more about Harris’ plans for the first hour, first day, first month and first year of her administration."

“It was a colossal failure for her campaign to shine the spotlight on Trump more than on Harris’s own ideas,” he added.

Ultimately, the winning coalition Harris needed to beat Trump never materialised, and voters' resounding rejection of Democrats showed that the party has a deeper problem than just an unpopular president.