New poll gives Democrat 62-point lead over her GOP rival among non-white voters
Hillary Clinton has said Donald Trump is "taking hate groups mainstream" with a campaign based on "prejudice and paranoia".
Speaking in Reno, Nevada, the Democratic presidential candidate linked her Republican rival with the "alt-right" movement, which opposes multiculturalism.
Mrs Clinton said his "disregard for the values that make our country great is profoundly dangerous".
"This is someone who retweets white supremacists," she added, charging him with "a steady stream of bigotry".
Mrs Clinton also slammed Mr Trump for appearing in Mississippi with former UKIP leader Nigel Farage, whom she described as "one of Britain's most prominent right-wing leaders".
She also said Mr Farage had "stoked anti-immigrant sentiments" to win June's referendum to have Britain leave the European Union.
"Farage has called for a ban on the children of legal immigrants from public schools and health services," she continued, "has said women are quote 'worth less' than men, and supports scrapping laws that prevent employers from discriminating based on race - that's who Trump wants by his side."
Mrs Clinton's campaign released an online video compiling footage of white supremacist leaders praising Mr Trump.
The businessman, who is trailing in the polls three months before election day, said earlier she was accusing his supporters "of being racists, which we're not".
He told a rally in Manchester, New Hampshire, it was "the oldest play in the Democratic playbook".
Mr Trump said his rival's speech would be a "brazen" bid to distract from questions about her family foundation and private emails.
He also accused Mrs Clinton of "a vast criminal enterprise run out of the State Department".
Mr Trump said revelations that scores of donors to the Clinton family foundation met with her as Secretary of State represents "one of the most shocking scandals in American political history".
"It's Watergate all over again," he said.
Meanwhile, a new poll has given Mrs Clinton a 62-point lead over her GOP rival among likely non-white voters.
The Quinnipiac University survey found that the Democrat leads Mr Trump 77% to 15% among minority voters.
White voters, by comparison, back the Republican by 52% – 11 points up on Mrs Clinton.
The poll gave her 60% support among women but only 42% among men.
Overall, Mrs Clinton holds a 10-point lead at 51%, with Mr Trump lagging behind at 41%.
In this very negative race, 64% of Trump supporters say they are voting mainly anti-Clinton, while 25% say they are voting pro-Trump.
Among Clinton supporters, 47% are mainly anti-Trump while 32% are pro- Clinton.