Tom Metzger, the notorious former Ku Klux Klan leader who rose to prominence in the 1980s while promoting white separatism and stoking racial violence, has died aged 82.
Riverside County Department of Public Health spokesman Jose Arballo Jr says Metzger died on November 4 at a skilled nursing facility in Hemet, California.
The cause was Parkinson's disease, Arballo said on Thursday.
The former grand dragon of the California chapter of the Ku Klux Klan became one of racism's most prominent figures after he left the organisation in the 1980s to form the White Aryan Resistance movement.
He eventually was pushed into the shadows and financial ruin, however, for his organisation's role in the 1988 beating death of Ethiopian college student Mulugeta Seraw in Portland, Oregon.
Seraw's family won a $US12.5 million ($A17.3 million) judgment against Metzger and others in 1990 following a trial in which a recording was played of Metzger praising the killers for performing their "civic duty".
Metzger lost his San Diego-area home, his television repair business and other assets.
Although left penniless, he continued to produce a racist newsletter for years and operated a racist hotline, taking calls personally.
He posted regularly on his organisation's website until just a few months ago, according to a brief biography announcing his death on the website.
"Tom Metzger spent decades working against core American values as one of the most visible hardcore white supremacists in the country," Anti-Defamation League CEO Jonathan A. Greenblatt said.
"Throughout his life, he engaged in a wide range of hateful activities from spreading anti-Semitic and racist rhetoric to launching vigilante border patrols as a California Klansman to recruiting skinheads to the white supremacist cause."
The killing of Seraw left racial wounds in Portland that continue to this day, said Randy Blazak, a former sociology professor at Portland State University who has written extensively about hate groups.
"We became known as Skinhead City. We had racist skinheads and anti-racist skinheads doing battle in the streets, which is sort of a precursor of antifa and the Proud Boys," he said, referencing those involved in recent violence that have gripped the city.
Born in Warsaw, Indiana, on April 9, 1938, Thomas Linton Metzger served in the Army from 1956 to 1959 before settling in California and a career as a TV repairman.
He joined the Knights of the Ku Klux Klan in the mid-1970s, rising to the role of grand dragon of California before leaving to form the White Aryan Resistance in the early 1980s.
He ran for Congress from northern San Diego County in the early 1980s, winning the Democratic Party primary but losing by a landslide in the general election after Democrats and Republicans united against him.
He became a prominent figure during those years, appearing on TV talk shows, organising white supremacist demonstrations and cross burnings and promising a white civil war that would result in "blood in the streets".
Tom Metzger's downfall began after he sent one of his White Aryan Resistance members to Oregon to organise a local Nazi skinhead group.
Within a month, local skinheads had beaten to death the 28-year-old Seraw with a baseball bat. They later admitted they singled him out because he was black.
Although long been identified as a white supremacist, Metzger shunned that term, saying he was a white separatist and didn't have a problem with blacks who did not interact with whites.