Driving around Milwaukee with a bumper sticker that reads "9/11 - The Big Lie," Rob Steinhofer gets a steady stream of hostile stares and obscene gestures.
But it was a drive to New York City for hearings before the federal commission investigating the 2001 terrorist attacks that convinced Steinhofer his government was engaged in a coverup.
"This is serious stuff, man," the 51-year-old engineer and musician said of his membership in Scholars for 9/11 Truth.
The organization contends that U.S. government officials were involved in bringing down the World Trade Center, or at least allowed it to happen, as a ruse for waging war in the Middle East.
Critics of the conspiracy theory have lashed out, trying to pressure the University of Wisconsin-Madison to fire faculty member Kevin Barrett because of his involvement with Scholars for Truth and his plans to include conspiracy theories in a class he is teaching on Islam.
Scripps Howard News Service found that more than one-third of the people answering its survey had suspicions about the U.S. government's role in the terrorist attacks.
The telephone poll of 1,010 adults, conducted at the Scripps Survey Research Center at Ohio University from July 6 to 24, has a margin of error of 4 percentage points.
"We're not, by any means, an isolated fringe group anymore," said Steinhofer, a leader of the Milwaukee Accordion Club.
Others who have enlisted in Scholars for Truth include a 73-year-old economist and former Republican, a Minnesota scientist-turned-political-activist and the son of a UW-Madison basketball coach.
Though none of them has faced threats to their employment as Barrett has, some have experienced alienation or backlash because of political beliefs most Americans find objectionable.
"Funny looks, sharp questions: Things like that go with the territory," said Michael Andregg, a professor in St. Paul, Minn., who studied genetics before deciding that war was a bigger threat to humanity than disease.
Although not ready to say U.S. officials carried out the attacks, Andregg said evidence suggests that the World Trade Center was brought down by internal explosions rather than by hijacked airliners.
"It looks a lot like a false-flag operation," the 54-year-old professor said, using a term usually applied to tactics intended to provoke war.
Among other assertions by the Scholars for Truth: that the towers collapsed too easily for steel skyscrapers; that U.S. air defenses responded too slowly once hijackings were reported; and that the government has withheld evidence crucial to a full investigation.
Outside the "9-11 truth movement," such arguments are mocked by many who support the government's investigation showing that Islamic extremists flew hijacked airliners into the twin towers and the Pentagon on Sept. 11, 2001.
Scotty Hettenbach, a UW-Milwaukee student whose father is an assistant to UW-Madison basketball head coach Bo Ryan, has drawn similar reactions on the Milwaukee campus while circulating fliers that question the government's role in Sept. 11.
"It's a coping mechanism for people to say, 'Hey, you're just a kook,' " said Hettenbach, 20, who joined the group last year.
The controversial group's Web site lists more than 200 members from throughout the academic world, as well as other professional backgrounds and assorted political organizations.
A bit reluctant to talk
Ben Seeling, 18, of Spring Valley, Wis., who joined as a recent high school graduate, said he has grown somewhat reluctant to discuss his Sept. 11 theories after some friends called him "ridiculous."
Seeling said he believes the U.S. government knew in advance of the terrorist attacks and perhaps orchestrated the devastation to justify the invasion of Iraq and other military missions.
"It's a lot to swallow," he said. "It's definitely something people would rather not hear about."
Until recently, Daniel Orr was a staunch Republican and conservative. Now living in Frankfort, Mich., the 73-year-old retiree shares his Sept. 11 conspiracy beliefs at church gatherings and elsewhere.
"I get responses that range from 'stunned' to 'outrage,' " he said. "My assessment is that this is not something that's gained adequate traction."
Andregg, who teaches at the University of Minnesota and at the private University of St. Thomas in St. Paul, said he always cautions students that his opinions about Sept. 11 should not automatically be accepted as fact.
Thomas Rochon, executive vice president of the University of St. Thomas, said administrators would never try to muzzle Andregg, even if they personally disagreed with his politics.
"He's an interesting and colorful personality," Rochon said. "We don't want to be monochromatic. And with Michael here, we won't be."