RALEIGH - Andy Silver, who was detained by police at the N.C. State Fair last weekend and threatened with arrest while wearing a sign calling for the impeachment of President Bush, is officially welcome back.

The ban on Silver's attendance was lifted Thursday, less than three hours after the American Civil Liberties Union weighed in on his behalf.

Katherine Lewis Parker, legal director of the state chapter of the ACLU, sent a letter to the attorney for the N.C. Department of Agriculture and Consumer Services protesting Silver's treatment by two State Capitol Police officers who kicked him out of the fair and threatened him with arrest if he returned.

Silver's photograph and description were posted on the "wall of shame" in the police command post, along with others banned after being caught selling drugs or stealing stuffed animals. Those on the wall are to be arrested on sight as trespassers.

Parker said the law officers violated Silver's constitutional right to free speech. "It's a First Amendment issue," Parker said. "State fairs are public fora."

David McLeod, a lawyer for the agriculture department, said Silver can return to the fairgrounds as long as he leaves his sign at home. He can wear his political message on a T-shirt, however.

"I think this was all a misunderstanding," McLeod said. "If you come out here to the fair, we've got all kinds of groups expressing all kinds of viewpoints. The content of the sign had nothing to do with it. We just don't allow people to walk around with signs because we don't want somebody to get poked in the eye."

Silver said he planned to return to the fair this weekend wearing an "Impeach Bush" T-shirt, but said he still thought he had a right to carry a sign.

"This isn't over," said Silver, who is part of the Grassroots Impeachment Movement.

McLeod's explanation that Silver's sign posed a safety hazard differed from other reasons given by state officials. Capt. O.D. Baldwin of the state agriculture department police said Wednesday that Silver had been kicked out because he didn't get a permit to display a sign, set up a booth or hand out materials.

On Thursday, Ag Police Chief Joel Keith said he knew of no such permit requirement.

Reached by phone Thursday, Baldwin said there was a requirement for those carrying signs to get clearance from the fairgrounds manager's office, though he was not aware of any written rule to that effect. He also repeated the reason Silver said he was originally given by police: that his message might cause a disruption and endanger him.

"We're a family deal here, with children and stuff," Baldwin said. "We have to be sensitive to causing conflicts. Like if you were a racist, hatred group and you wanted to come out here and put your literature out here, we wouldn't allow that because it would offend other people. It's a judgment the officer will make at the time, whether it's vulgar or improper."

Asked whether Silver's impeachment message amounted to "hate literature," Baldwin replied, "It is if you like the president."

Parker, with the ACLU, didn't buy that argument.

"If someone were to take offense and try to attack him, which nobody suggests happened, it would be the officer's duty to make sure he wasn't assaulted," she said. "They should be focused on someone who's actually violating the law rather than preventing someone from exercising their constitutional rights."