We need to beware of the right-wing militia movement in America. It poses a danger to our democracy. And shamefully, it is fueled by a few mainstream politicians and media personalities.

After a decade out of the spotlight, the militant rightwing “Patriot” movement — which was responsible for such murderous terrorist acts as the 1995 Oklahoma City bombing that claimed 168 lives and injured 500 — is on the rise.

And according to a new report from the Southern Poverty Law Center, this violent coalition of groups is united in their hatred of the government, and of the first black president.

The newly minted report, “The Second Wave: Return of the Militias,” warns that authorities are worried about the acceleration in violent acts by radical right groups.

“Militiamen, white supremacists, anti-Semites, nativists, tax protesters and a range of other activists of the radical right are cross-pollinating and may even be coalescing,” says the report. “This is the most significant growth we’ve seen in 10 to 12 years,” according to one source in the report. “All it’s lacking is a spark. I think it’s only a matter of time before you see threats and violence.”

As many as 50 new militia training groups have formed in two years. Shockingly, one of the groups, the Oath Keepers, consists of current and ex-soldiers and police officers. Its members are concerned about a coming dictatorship, concentration camps and a “New World Order.” And they regard President Obama as “an enemy of the state.”

Meanwhile, sales of guns and ammunition have increased over fears of gun control laws.

The Southern Poverty Law Center notes that in recent months, men with pro-militia, racist, anti-government or anti-Semitic sentiments have committed acts of murder — including the murder of six police officers since April. And a majority of the killers and conspirators were at least partially motivated by the election of Obama.

It’s astonishing that mainstream politicians and media outlets have stoked the fires of militia extremism. This is both irresponsible and dangerous, and will only lead to acts of violence. They have legitimized the hateful and racist propaganda of the Patriot groups, including the outrageous claim that the president is not a U.S. citizen, and that he presides over a fascist-socialist government.

Glenn Beck of Fox News has called Obama a Marxist and a racist who hates white people. And he has linked the Obama administration with fascism. CNN’s Lou Dobbs has opened the door for questioning Obama’s citizenship, and has legitimized the conspiracy theories about Latinos wanting to conquer the Southwest.

Rep. Michele Bachmann, R-Minn., suggested that the president was planning reeducation camps for young people. Rep. Spencer Bachus, R-Ala., channeling Joe McCarthy, warned that there are 17 “socialists” in Congress. And Texas Gov. Rick Perry echoed militia talk when he suggested Texas secede from the Union.

These militia sentiments were on full display at the anti-tax tea party protests, and they have continued at the health care town hall meetings, along with death threats against members of Congress. Some protestors have come to presidential events strapped with pistols and armed with semiautomatic assault rifles, creating conditions that are ripe for violence.

We can’t ignore the threat of homegrown domestic terrorism. The far right militia groups are profoundly undemocratic. We underestimate them at our peril.

David A. Love is a writer and human rights advocate based in Philadelphia. His blog is davidalove.com. He can be reached at pmproj [at] progressive [dot] org.