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Jewish groups condemned Friday the invocation of Nazi Germany that has seeped into the health care reform debate at town hall forums in recent days.

David A. Harris, president of the National Jewish Democratic Council, called the Nazi references "not funny" and "profoundly troubling."

"At these too-well-organized 'mad as hell and we're not going to take it anymore' town hall meetings around the country this August, more and more of these disturbing Nazi comparisons are cropping up -- and they all seem to be coming from the heart of the Republican base," he said. "And it has to stop."

Town hall audiences and conservative bloggers protesting a Democratic-sponsored bill on health care reform have used the offensive imagery to liken President Obama's plan to how the Nazis treated prisoners in concentration camps.

Supporters of the bill have for their part suggested the angry "mobs" are reminiscent of Adolf Hitler's blind followers. Some lawmakers say they have canceled public meetings because they fear for their lives.

Harris acknowledged that both sides were guilty.

"I strive to stick to my principles on this one, and my organization calls out folks on both sides of the aisle who engage in inappropriate Holocaust comparisons and Nazi rhetoric," he said.

The White House also denounced the use of Nazi imagery in the health debate.

"I think anytime you make references to what happened in Germany in the '30s and '40s, I think you're talking about an event that has no equivalent," White House spokesman Robert Gibbs said Friday. "And I think anytime anyone ventures to compare anything to that, they're on thin ice and it's best not deployed."

Gibbs argued for a robust debate without resorting to low blows.

"The president strongly believes we can do so without yelling at each other, without pushing each other, without degrading each other, and do so in a way I think that respects the difference in all of our opinions," he said.

On Thursday, Rep. Brian Baird, D-Wash., who is replacing a town hall meeting for a conference call in his district, compared his constituents' behavior to Nazi-era adherents.

"What we're seeing right now is close to Brown Shirt tactics," Baird told a local newspaper. "I mean that very seriously."

"In an interview Wednesday, House Speaker Nancy Pelosi said of the protesters, "I think they are Astroturf, you be the judge," using an expression that refers to orchestrated grassroots.

"They're carrying swastikas and symbols like that to a town hall meeting on health care," she said.

Ken Spain, a spokesman for the National Republican Congressional Committee, called such remarks evidence that Democrats are "desperate to climb their way out of message quicksand."

A spokesman for Pelosi told FOXNews.com that the speaker was referencing a photo taken at a town hall meeting hosted by Rep. Ed Markey, D-Mass., which showed a protester holding a sign of a swastika crossed out over Obama's name and a question mark.

Another protestor at Rep. Lloyd Doggett's town hall meeting in Texas reportedly was seen with an SS symbol. Separately, one protester reportedly compared Massachusetts Rep. Jim McGovern to Josef Mengele, who conducted medical experiments on concentration camp prisoners.

At some events, protesters have been excessively boisterous in other ways. An image captured at Doggett's town hall showed someone holding a poster with devil's horns painted on the congressman's head. A Democratic National Committee Web ad contains an image of a constituent standing outside Rep. Frank Kratovil's office carrying a hanging effigy of the congressman.

Rep. Brad Miller, D-N.C., said he will not host any town halls this month because offices have received threatening phone calls, including one directed against his life. Instead, he will hold one-on-one meetings about health care reform with constituents.

Miller's office turned the death threat over to the Capitol Police.

"We are looking into the matter," Sgt. Jessica Baboulis, a spokeswoman for the U.S. Capitol Police, told FOXNews.com.