PHILADELPHIA – As supporters walked into the first rally for US Vice-President Kamala Harris and Minnesota Governor Tim Walz, they were given light-up wristbands like the ones pop star Taylor Swift’s fans wear at her concerts.

       It was clear this was no longer President Joe Biden’s campaign.

       Seemingly overnight, the new Democratic ticket transformed the party’s presidential push from a dreary drag to – as Mr Walz put it – “a joy”. The cross-country unveiling showcased an enthusiasm that more than a few Democrats say has not been on display since Mr Barack Obama’s first presidential campaign.

       The Biden-to-Harris swop has, in just three weeks, flipped the election on its head. Democrats can now avoid making the race a referendum on Mr Biden – a contest that many worried they would lose – and instead cast it as a choice between a Harris-led future or a return to power by former president Donald Trump. Across the country, the Vice-President’s crowds have been chanting her refrain: “We’re not going back.”

       Here are five striking themes that coursed through the first week of the Harris-Walz ticket.

       Ms Harris is campaigning as if she is winning, even as she cautions Democrats that she and Mr Walz remain the “underdogs” against Trump.

       In a remarkable development, Ms Harris has turned Mr Biden’s alarming poll numbers around. She now leads Trump in a national polling average and has pulled ahead in the must-win Northern battleground states of Michigan, Pennsylvania and Wisconsin, according to new surveys from The New York Times and Siena College.

       “We’re going to do this,” she told the crowd at her Aug 9 rally in Arizona.

       On the other side, Trump finds himself in an unfamiliar position: the back foot. He has challenged Ms Harris to three debates, a move typically made by a candidate who fears defeat. She has so far agreed to only one.

       On Aug 8, he held a news conference at Mar-a-Lago, his resort in Palm Beach, Florida, to try to reclaim the spotlight, flashing frustration about the size of Ms Harris’ crowds and repeating falsehoods that only drew more attention to his role in the Capitol riot on Jan 6, 2021. Some of his lines of attack on Ms Harris, such as questioning her racial identity, have been less than politically wise. And his running mate Senator J.D. Vance has hardly set the campaign trail alight.

       “It’s been a pretty damn good week,” said Democratic Representative Mark Pocan, who had publicly called for Mr Biden to drop out. “Night and day isn’t enough of a contrast.”

       Mr Biden for years cast Trump as something of a cancer on the country who had worked to undermine elections, roll back fundamental rights and pit Americans against one another.

       Ms Harris and especially Mr Walz have a new approach: mocking him.

       It was Mr Walz’s description of Trump as “weird” that helped pave the way for him to win the running-mate sweepstakes. In stump speeches, he calls Trump and Mr Vance “creepy and weird”. And one of the biggest Walz applause lines last week was when he reminded audiences that violent crime was up during the Trump era – “not even counting the crimes he committed”.

       Ms Harris has not held back, either. During her first large campaign rally in Atlanta, she effectively called Trump a coward for waffling on whether he would debate her.

       “Well, Donald, I do hope you’ll reconsider to meet me on the debate stage,” she said, before drawing out the next line for maximum effect: “Because as the saying goes, ‘If you’ve got something to say, say it to my face.’”

       With tens of thousands of people crowding into rallies, and hundreds of millions of dollars pouring in, the Harris campaign is surely asking: Why mess with a good thing?

       One way to do that, potentially, would be for Ms Harris to sit down for a formal interview with the news media – which she has not yet done, three weeks after Mr Biden dropped out and endorsed her. She has struggled in such settings before, especially early in her tenure. Any gaffes, real or perceived, could take the shine off her tightly controlled roll-out as the Democratic nominee.

       Ms Harris has also not yet laid out her policy agenda, and her website does not include a page detailing her policy positions, although it is still early in her campaign and she is unlikely to diverge much from Mr Biden.

       In brief remarks to reporters on Aug 10, she said she planned to deliver a policy platform this week.

       Trump is trying to make Ms Harris’ media-shy approach a campaign issue, accusing her of hiding from tough questions. But there is little evidence the subject matters much to voters.

       On Aug 10, Ms Harris took five questions from her travelling press pool in Las Vegas.

       And she told reporters last week, in a 70-second Q&A on an airport tarmac in Michigan, that she planned to hold a sit-down interview soon – but not that soon.

       “I’ve talked to my team,” Ms Harris said. “I want us to get an interview scheduled before the end of the month.”

       The last Democratic presidential campaign that produced partywide, unencumbered enthusiasm was Mr Obama’s in 2008. His 2012 re-election was a slog, followed by former candidate Hillary Clinton’s often-perfunctory 2016 bid and Mr Biden’s consensus-minded and Covid-interrupted 2020 run.

       The 2024 Biden experience was on track to be another eat-your-vegetables campaign for Democratic voters. But once he dropped out and Ms Harris took charge, 16 years of waiting for new inspiration came rushing out, seemingly all at once.

       Gone were Mr Biden’s low-energy, small-room stops where he mumbled off script. Last week, the Harris-Walz rollout included a drum line in Philadelphia, a hipster folk band in Wisconsin and the largest Democratic campaign rally since the Obama days in Detroit.

       Singing and dancing were widespread in the hours before Ms Harris and Mr Walz took the stage. In Philadelphia, online influencers had their own entrance to the arena. Musicians, actors and athletes offered to help. Nobody used to spend any time wondering if a shadowy silhouette in a Swift post on Instagram was a low-key Biden endorsement – but the internet lit up last week when one looked like Ms Harris.

       “Before President Biden dropped out, people would say the 2028 primary is so great because you’ll have young governors and new people and a shift generationally, and in a lot of ways, this sped that up,” said Pennsylvania Governor Austin Davis, who was at the kick-off rally in Philadelphia. “The switch lit the match.”

       For her partner on the ticket, Ms Harris wanted someone she clicked with personally. So far at least, Mr Walz has seemed to deliver.

       At their first joint appearance last week in Philadelphia, Mr Walz’s beaming, open-mouthed smile gave the impression of a man who could scarcely believe where he was standing. Ms Harris appeared delighted as she told the crowd his life story, repeatedly referring to him as “Coach Walz”, a nod to his days coaching high school football.

       They have travelled the battlegrounds since then, campaigning in Wisconsin, Michigan, Arizona and Nevada.

       Representative Haley Stevens, who spoke at the Harris-Walz rally in Detroit on Aug 7, said the new running mates were campaigning “like they’ve always been doing this” together.

       “When he looks at Kamala Harris and he says, ‘Thank you for bringing back the joy,’ that is such a resonant message,” Ms Stevens said. “Because people are so sick of darkness and negativity and fear.”

       Trump and Mr Vance have hardly seemed to establish the same rapport. Asked in July if the Ohio senator was “ready on Day One” to serve as president if the need arose, Trump avoided directly answering the question.

       “Historically, the vice-president – in terms of the election – does not have any impact,” he said.

       He and Mr Vance have appeared together at only three rallies. NYTIMES