Alien supporters of a Marxist Palestinian group may not be deported because even non-citizens have the First Amendment right to espouse anti-American beliefs, a judge ruled in gutting a McCarthy-era law.

"In this case, the government is trying to stifle certain ideas from entering our society from certain aliens," U.S. District Judge Stephen V. Wilson said."Our society, however, was built on the premise that only through the free flow of ideas can our nation grow and prosper."

Wilson's ruling Thursday struck down four provisions of the 1952 McCarran-Walter Act that allowed the government to deport aliens who advocated or were associated with groups espousing anti-American ideologies including communism.

He said the sections of the law passed during a time when Sen. Joseph McCarthy, R-Wis., was whipping up Cold War fears against communism were "overbroad" and could cause deportation for something as simple as wearing a political button.

"Now I feel I can speak freely. I did not an hour ago," said Khader Hamide, 34, one of the eight defendants the government had sought to deport for allegedly supporting the Popular Front for the Liberation of Palestine, a Marxist member of the Palestine Liberation Organziation.

In his ruling, Wilson also threw out an exception to a 1987 law that recognized free speech rights in deportation proceedings for all immigrants except members of the PLO.

Wilson acknowledged world concern over terrorist threats but said his decision would not interfere with Congress' ability to enforce laws already in place to deal with terrorism.

"Our decision ... today will not significantly deplete the government's arsenal in combating terrorism," said Wilson, whose ruling applies only to central and southern California.

Michael P. Lindemann, the Justice Department's lead attorney in the case, said the ruling would be appealed. He declined further comment.