As part of Hillary Clinton’s continuing strategy to turn the US presidential election into a referendum on Donald Trump, the Democrat struck a heavy blow on the New Yorker in a speech on Thursday that sought to place the billionaire firmly on a far-right perch.

Clinton’s speech in Nevada, a battleground state with a large Hispanic population, was part of an exchange of racially loaded accusations this week with the Republican nominee.

Her speech, one of the best of her campaign, was aimed at pre-empting any efforts by the Trump campaign to rebrand itself.

It had the added bonus of pushing down the news agenda Trump’s “corruption” charges over her relationship with donors to her Clinton Foundation charity during her time as secretary of state.

Suffering from falling poll numbers, Trump has appeared, at times confusingly this week, to be pivoting on his hard-right immigration policies to appeal to electorally important minority voters so alienated by this rhetoric. Clinton, in her speech, reminded voters of his past inflammatory remarks and the support he enjoys among far-right groups.

“From the start, Donald Trump has built his campaign on prejudice and paranoia,” she said, referring to his slandering of Mexican immigrants as “rapists”.

Clinton went for the jugular in Nevada. Questioning again whether Trump has the character to be the US president, she highlighted his ties to the “alt-right” (alternative-right) movement that peddles white nationalism, misogyny, anti-Semitism and xenophobia, describing the movement as “an emerging racist ideology”.

“A man with a long history of racial discrimination, who traffics in dark conspiracy theories drawn from the pages of supermarket tabloids and the far reaches of the internet, should never run our government or command our military,” Clinton said.

Conspiracy theories

Her speech came the day after Trump told an almost exclusively white audience in Mississippi, a state with proportionately one of the largest black populations, that Clinton is “a bigot who sees people of colour only as votes, not as human beings worthy of a better future”.

Clinton jabbed Trump back on his “steady stream of bigotry”.

Clinton’s attack came a week after Trump recruited Steve Bannon as his campaign chief executive. Bannon is executive chairman of Breitbart News, the provocative online site which the former investment banker has boasted is “the platform of the alt-right”. (A Breitbart contributor once told me that his job was to “throw a turd in the punch bowl”.)

“He’s taking hate groups mainstream and helping a radical fringe take over one of America’s two political parties,” said Clinton.

Embracing the fringe right is not new in a US presidential election politics. Conservative Barry Goldwater’s 1964 White House campaign actively sought the support of the John Birch Society, a group considered a radical right organisation. (The Republican lost by a landslide.)

What is unprecedented in this year’s race is the recruitment of an activist from the far-right by a mainstream presidential candidate to a position where he can shape the campaign.

“They are bringing back into public discourse language and ideas that were really forced out of mainstream public discourse in the 1960s, whether it is expressing certain racial beliefs or racist beliefs or advocating policy such as a complete ban on immigration from a particular religious group,” said Michael Flamm, professor of history at Ohio Wesleyan University and author of In the Heat of the Summer: The New York Riots of 1964 and the War on Crime.

The success of Trump’s insurgent campaign has certainly made it acceptable for supporters to level accusations and express themselves freely in racially tinged language.

At a rally outside Philadelphia on Tuesday, Trump supporter Ken Hissner (72), a retiree from Chester County, Pennsylvania, told me why he dislikes President Barack Obama while he waited for the Republican’s running mate Mike Pence to speak.

“I try to tell black people, I say, ‘Listen, he’s keeping you on the plantation.’ Milwaukee has never had a Republican since like 1906 and you see the problem that’s going on there,” he said, referring to the violent protests there this month after the police killing of a black man.

“Her [Clinton] and Obama, they don’t like the police, they don’t like the military, they don’t like Israel. For him [Obama] to say he is a Christian is a disgrace. He caters to the bad guys, not the police. He caters to white over black [sic], even though he’s a zebra.”