Launched in March by Las Vegan Stewart Rhodes, Oath Keepers bills itself as a nonpartisan group of current and retired law enforcement and military personnel who vow to fulfill their oaths to the Constitution.

More specifically, the group's members, which number in the thousands, pledge to disobey orders they deem unlawful, including directives to disarm the American people and to blockade American cities. By refusing the latter order, the Oath Keepers hope to prevent cities from becoming "giant concentration camps," a scenario the 44-year-old Rhodes says he can envision happening in the coming years.

It's a Cold War-era nightmare vision with a major twist: The occupying forces in this imagined future are American, not Soviet.

"The whole point of Oath Keepers is to stop a dictatorship from ever happening here," Rhodes, a former Army paratrooper and Yale-trained lawyer, said in an interview with the Review-Journal. "My focus is on the guys with the guns, because they can't do it without them.

"We say if the American people decide it's time for a revolution, we'll fight with you."

That type of rhetoric has caught the attention of groups that track extremist activity in the United States.

In a July report titled "Return of the Militias," the Alabama-based Southern Poverty Law Center singled out Oath Keepers as "a particularly worrisome example of the Patriot revival."

The Patriot movement, so named because its adherents believe the federal government has stepped on the constitutional ideals of the American Revolution, gained traction in the 1990s and has been closely linked to anti-government militia and white supremacist movements.

The movement is blamed for spawning Timothy McVeigh, who bombed a federal building in Oklahoma City in 1995, killing 168 people.

"I'm not accusing Stewart Rhodes or any member of his group of being Timothy McVeigh or a future Timothy McVeigh," law center spokesman Mark Potok said. "But these kinds of conspiracy theories are what drive a small number of people to criminal violence. ... What's troubling about Oath Keepers is the idea that men and women armed and ordered to protect the public in this country are clearly being drawn into a world of false conspiracy theory."

Oath Keepers got some unwanted attention in April when an Oklahoma man loosely connected to the group was arrested for threatening violence at an anti-tax protest in Oklahoma City. Rhodes called the man "a nut" who had no real affiliation with his group.

Nonetheless, Potok's group now monitors Oath Keepers on its Web site blog "Hatewatch."

Oath Keepers is not preaching violence or government overthrow, Rhodes said. On the contrary, it is asking police and the military to lay down their arms in response to unlawful orders.

The group's Web site, www.oathkeepers.org, features videos and testimonials in which supporters compare President Barack Obama's America to Adolf Hitler's Germany. They also liken Obama to England's King George III during the American Revolution.

One member, in a videotaped speech at an event in Washington, D.C., calls Obama "the domestic enemy the Constitution is talking about."

According to the law center, militia groups are re-emerging in this country partly as a result of racial animosity toward Obama.

It's the "cross-pollinating" of extremist groups -- some racist, some not -- that is of concern, Potok said. As evidence that the danger is real, he points to several recent murders committed by men with anti-government or racist views.

The U.S. Department of Homeland Security reached a similar conclusion in a report earlier this year about the rise of right-wing extremism. The report said the nation's economic downturn and Obama's race are "unique drivers for right-wing radicalization and recruitment."