Kamala Harris has cast herself as the "underdog" in the US presidential race and called her opponent Donald Trump "just plain weird," while Trump painted the vice president as "evil," "sick" and "unhinged" as the rivals exchanged barbs.
The duelling appearances capped a whirlwind week that saw Harris ascend to the top of the Democratic ticket after President Joe Biden, 81, dropped his re-election bid under mounting pressure from his fellow Democrats. A series of polls indicate Harris' entry erased the lead Trump had enjoyed over Biden in a matter of days.
Harris, speaking at a private fundraiser headlined by singer-songwriter James Taylor in Pittsfield, Massachusetts, said much of the rhetoric coming from Trump and his running mate, US Senator JD Vance, was "just plain weird."
Her use of the word "weird" to describe her opponents was part of a new strategy from Democrats. The Harris campaign called Trump "old and quite weird" following his appearance on Fox News on Thursday, and at least one supporter showed up outside Saturday's event holding a sign proclaiming "Trump is weird."
As she did during a blitz of campaign stops this week, Harris again contrasted her background as a prosecutor with Trump's record as a convicted felon and said her bid was about the future, while Trump wanted to return the country to a "dark past."
Hours later, Trump unleashed a barrage of hyperbolic attacks at a rally in St Cloud, Minnesota, asserting that Harris would "destroy the country" and criticising her on issues ranging from public safety to immigration.
"If a crazy liberal like Kamala Harris gets in, the American dream is dead," Trump said, adding that Harris is "even worse" than Biden.
The former president's speech - suffused with familiar grievances and false claims about election fraud - made clear that his short-lived call for unity following the attempt on his life two weeks ago had dissipated altogether.
"I want to be nice. They all say, 'I think he's changed,' Trump said. "No, I haven't changed. Maybe I've gotten worse."
Trump said on Saturday in a post on his Truth Social site that he would continue to hold outdoor rallies and he believed the Secret Service was capable of protecting him.
Minnesota has not chosen a Republican presidential candidate in 52 years, but the Trump campaign had viewed it as increasingly within reach after Biden's poll numbers dipped following his disastrous June 27 debate performance.
Harris' takeover, however, has re-energised a campaign that had faltered badly amid Democrats' doubts about Biden's chances of defeating Trump, 78, or his ability to continue to govern should he succeed.
Harris, the first Black woman and first Asian American to serve as vice president, raised more than $US100 million in the 36 hours after Biden's departure. Saturday's fundraiser brought in more than $US1.4 million from some 800 attendees, her campaign said.
Trump and Vance, 39, have attempted to tie Harris to what they say is the Biden administration's failure to corral high inflation and stem a surge of migrants at the southern border with Mexico. Trump asserted that Harris was "even worse" than Biden in his conference remarks.
Earlier on Saturday, Trump addressed a cryptocurrency conference in Nashville, part of a broader Republican effort to court crypto enthusiasts ahead of the November 5 election.
He vowed to make the US the "crypto capital of the world," a far cry from his stance in 2021, when he called bitcoin a "scam." Trump warned that China and other countries would embrace crypto if the US did not and promised industry-friendly regulations if elected. China currently bans cryptocurrency.
