OLUMBIA, S.C., April 23 — At the time, Brett A. Bursey says, he seemed to be having a 60's flashback.
There he was at the Columbia Metropolitan Airport with his antiwar sign. There were the thousands of Republicans gathering to welcome a president. There were the police officers arresting him for trespassing.
The first time this happened was in May 1969, before a visit by Richard M. Nixon. The charges against Mr. Bursey were dropped after the South Carolina Supreme Court ruled that if protesters were on public property — as the antiwar demonstrators were — they could not be charged with trespassing.
Last Oct. 24, 33 years later and about 100 yards away, the now graying Mr. Bursey was again arrested for trespassing, this time before a visit by President Bush. The charge was soon dropped.
But last month, the local United States attorney, J. Strom Thurmond Jr., brought federal charges against Mr. Bursey under a seldom-used statute that allows the Secret Service to restrict access to areas the president is visiting. He faces six months in jail and a $5,000 fine.
This being South Carolina, Mr. Bursey's story includes lots of colorful history, old grudges and improbable plot twists, not to mention the Confederate battle flag.
But to some legal experts it is also part of a growing pattern of repression against protesters, demonstrators and dissenters. The American Civil Liberties Union says it has found many examples, like increased arrests and interrogations of protesters and the shunning of celebrities who have opposed the war in Iraq.
"When you connect the dots, you see very clearly a climate of chilled dissent and debate," said Anthony D. Romero, executive director of the civil liberties group.
In particular, Mr. Romero said, there is a growing practice of corralling protesters in "free-speech zones," which are often so far from the object of the protest as to be invisible. "It's an effort to mitigate the effectiveness of free speech," he said.
And he does not buy the argument that such zones are necessary to protect the president and other officials. "John Hinckley wasn't carrying an anti-Reagan sign when he shot him," Mr. Romero said.
It was just such a "protest zone" that got Mr. Bursey in trouble last fall. A spokeswoman for the airport said officials there had established a protest area on the verge of a highway, a good half mile from the hangar where the president would be speaking. (Airport police are not sure if anyone actually protested at the official zone, she said.)
Mr. Bursey hoped he and some friends could protest somewhere closer, maybe across the road from the hangar, he said. The police in Charleston and Greenville had been accommodating, he said, when he had asked to avoid the protest zones, which he described as being "out there behind the coliseum by the Dumpsters."
It did not work this time.
"We attempted to dialogue for a while, them telling me to go to the free-speech zone, me saying I was in it: the United States of America," Mr. Bursey said. Finally, he said, an airport policeman told him he had to put down his sign ("No War for Oil") or leave.
" `You mean, it's the content of my sign?' I asked him," Mr. Bursey said. "He said, `Yes, sir, it's the content of your sign.' "
Mr. Bursey kept the sign and was arrested; he said he watched Air Force One land from the back of a patrol wagon and spent the night in the county jail.
A Secret Service agent was present at the arrest, Mr. Bursey said, but he added that no one could have seen him and his companions as a security threat. "There was no one under 50 in that crowd," said Mr. Bursey, who is 54. "In my mind, at that time, we didn't pose a security threat; we posed a political threat."
A spokesman for the United States attorney's office, Scott N. Schools, said the message on the sign was not the problem. "It's not the fact of what Mr. Bursey was doing," Mr. Schools said. "The problem was where he was doing it. That's the basis of the prosecution."
Mr. Schools did allow that federal prosecutions of protesters at presidential events had been rare.
