US vice president Kamala Harris appears to have energised Democrats in the early days of her candidacy for the White House.

A surge in warm feelings extends across multiple groups, including some key Democratic constituencies that had been especially tepid about President Joe Biden, a new poll shows.

About eight in 10 Democrats say they would be somewhat or very satisfied if Ms Harris became the Democratic nominee for president, according to the survey from The Associated Press-NORC Centre for Public Affairs Research.

The research was conducted after Mr Biden withdrew from the race for the White House.

In a separate AP-NORC poll, taken before Mr Biden dropped out but after his disastrous debate against former President Donald Trump, only about four in 10 Democrats said they were somewhat or very satisfied that he was the Democratic Party’s likely nominee for president.

The rapidly changing views among Democrats in such a short time span underline how swiftly the party – from rank-and-file voters to elected officials – has coalesced behind Ms Harris as its standard-bearer, motivated by the fresh face at the top of the ticket and newfound confidence in the party’s prospects against Mr Trump in November.

Gary Hines, a Democrat from Philadelphia, said he was not particularly impressed by Ms Harris’ first presidential bid but now she has shown “she’s up to the task, can do the work, has proven that she’s running a strong campaign so far, and maybe on a bigger level, she’s somebody that can beat Donald Trump”.

All those factors have ignited an enthusiasm in Mr Hines that was not there when Mr Biden was still in the race, he said.

“I really want to go out and maybe knock on doors, which I would’ve never done,” said Mr Hines, 68. “It’s jazzed me up quite a bit.”

Americans are also more likely to say that Ms Harris would make a good president than they were earlier in July, a shift that was primarily driven by Democrats.

They still see a tough contest looming, though – a majority of US adults, 56%, say that if Mr Trump and Ms Harris are their parties’ nominees for the general election in November, Mr Trump is more likely to win.

Lauren Schulman, a Democrat from Pompano Beach, Florida, said she admires Mr Biden and what he has accomplished during his presidency. But she said with him at the top of the ticket, “I have just been so terrified that we were going to lose”.

With Ms Harris, on the other hand, “she’s been a bright, shining star,” said Ms Schulman, 66, noting that the vice president is “smart and she’s younger, and she even comes off younger than she is. That makes such a huge contrast with Trump”.

About seven in 10 black adults and about half of Hispanic adults would be satisfied with Ms Harris as the Democratic nominee – a marked increase from earlier in July, when about half of black adults and 15% of Hispanic adults felt satisfied with Mr Biden as the Democrats’ expected nominee.

The share of younger adults (those under the age of 45) who say they would be satisfied with Ms Harris as the nominee, at around four in 10, is higher than the 17% who said they were satisfied with Mr Biden in July.

Bryan Seigler, a Democrat from Raleigh, North Carolina, praised Ms Harris’ “broad appeal” and pointed to a contrast that Democrats were not able to make before.

“Donald Trump is the old guy now,” said Mr Seigler, 36.

The new poll shows that Ms Harris’ overall favourability has risen slightly, from 39% at the beginning of the summer – before the debate – to 46% now.

Democrats’ opinions of Ms Harris have also shifted in a slightly more positive direction. Eight in 10 Democrats have a positive view of her, up slightly from around seven in 10 in early June.

Ms Harris would be a historic candidate – she would be the first woman to win the US presidency, as well as the first black woman, the first South Asian American, and the first Asian American.

Around four in 10 Americans say that it would be a good thing for the country to elect either a woman or a person of colour to be president. Even more – about six in 10 when asked about electing a person of colour and about half when asked about electing a woman – say it does not matter.

Majorities of Democrats, however, say it would be good for the country to elect a woman or person of colour.

Most Americans – 54% – say they have heard or read a lot about Mr Biden’s decision to withdraw from the 2024 presidential race. About three-quarters of Americans approve of his decision to withdraw as the Democratic nominee for president, including most Democrats and Republicans.

However, US adults say that if Mr Trump and Ms Harris are the candidates, Mr Trump is more likely to win. About nine in 10 Republicans say Mr Trump is more likely to become US president, while only about seven in 10 Democrats say that about Ms Harris.