American white supremacist Frazier Glenn Miller Jr. was recently convicted of capital murder, reinforcing the thesis that the overwhelming majority of extremist-related murders in the United States in the last decade have been committed by racists of his ilk.

Miller, a former Ku Klux Klan leader, attacked two Jewish institutions in Kansas on April 13, 2014, killing three people, all of whom, ironically, were Christians.

Intent on murdering Jews, Miller drove to the Jewish Community Center of Greater Kansas City in Oakland Park and opened fire, fatally striking Dr. William Corporon, 69, and his 14-year-old grandson, Reat Underwood. He then drove to a nearby assisted living center, Village Shalom, where he shot and killed a 53-year-old employee, Terri La Manno.

At his trial, Miller, 74, a dyed-in-the-wool antisemite, said he had acted in the defence of the white race. “Everything I did for our people, to secure the existence of our people and the future of white children,” he told a white jury.

Miller’s sentencing date is on October 30. He will either be sentenced to death or given a life sentence without parole.

The Miller trial unfolded shortly after Dylann Storm Roof, a young white supremacist, was accused of murdering nine worshippers at an African American church in Charleston, South Carolina, this past June.

In 2012, the white supremacist Wade Michael Page killed six people at a Sikh temple in Oak Creek, Wisconsin.

According to a report released by the Anti-Defamation League in July, 83 percent of the perpetrators of extremist-related murders since 2005 have been white racists. Their 14-word slogan echoes Miller’s rant, “We must secure the existence of our people and a future for white children.”

White supremacists believe that white Christians are doomed by a rising non-white population, which, they claim, is controlled and manipulated by Jews.

Jews, they maintain, constitute an evil and separate parasitic race.

The ADL notes that white supremacist violence has escalated since the election of America’s first black president, Barack Obama.

White supremacists operate both as individuals and in groups, but most remain unaffiliated. The Internet allows them to keep in touch with each other, the ADL says.

White supremacists are divided into various factions — traditional racists, neo-Nazis, racist skinheads, Christian Identity members and white supremacist prison gangs.

The Ku Klux Klan dominated the American racist scene in the first third of the 20th century, but has since declined and splintered into 40 to 50 organizations, from the Knights of the Ku Klux Klan to the Mississippi White Knights.

The most influential American racist leaders in the past 60 years — George Lincoln Rockwell of the American Nazi Party, William Pierce of the National Alliance and Richard Butler of Aryan Nations — have passed on.

Among the most prominent ones today are reportedly Morris Gullet of the Church of Jesus Christ Christian and Jeff Schoep of the National Socialist Movement.

White supremacists occupy a dark space on the lunatic fringe and do not pose a significant threat to American democracy. But they’re highly motivated, prone to violence, judging by the Roof and Miller cases, and should be monitored very carefully.

They’re the cancerous scabs on the American body politic.