KEEP OUT.(The Talk of the Town)

There is an American tradition of responding to threats by confusing thoughts with acts and temporarily forgetting what Jefferson set down, in 1779, as one of the country's founding principles: "that truth is great and will prevail if left to herself, that she is the proper and sufficient antagonist to error, and has nothing to fear from the conflict, unless by human interposition disarmed of her natural weapons, free argument and debate." The modern legislative history of banning undesirable opinions from American shores began in 1918, when Congress passed the Anarchist Act, which was designed to keep out people with subversive ideas. In 1952, as the McCarthy era was reaching its hysterical phase, the Immigration and Nationality Act, better known as McCarran-Walter, added Communists to the list of aliens to be excluded from entry. In the following years, Graham Greene, Gabriel Garcia Marquez, Pablo Neruda, and Dario Fo were denied visas.

In the age of terror, the Patriot Act denies entry to anyone who materially supports a terrorist organization, which is defined in hopelessly broad terms as any group of two or more people who intend to kill or inflict harm upon others. Among many thousands of foreigners, the law has kept out the Swiss-Egyptian scholar Tariq Ramadan. Ramadan is a grandson of the founder of the Muslim Brotherhood and is an Islamist himself. He argues for a large role for religion in Arab-Muslim states and an assertion of Muslim identity alongside citizenship in Western democracies. (Some critics accuse him of concealing more radical views; their evidence is thin.) His lectures and his books on Islam and the West have gained him a following among young European Muslims. In 2004, Ramadan was given a tenured appointment at the University of Notre Dame. He had rented a house in South Bend, shipped his furniture there, and enrolled his children in Indiana schools, when the State Department, acting on secret information from the Department of Homeland Security, revoked the visa that it had granted him. It has taken two years of repeated applications and inquiries, as well as a lawsuit by American civil-liberties, academic, and literary organizations, for Ramadan to receive an official explanation: between 1998 and 2002, he donated about seven hundred and seventy dollars to a pro-Palestinian French charity that was suspected of channelling money to Hamas, and which did not appear on the State Department's blacklist until 2003. Ex post facto, Ramadan has run afoul of the Patriot Act.

It's hard to shake the suspicion that what has really kept Ramadan out is his ideas. State and Homeland Security have interpreted the language of the Patriot Act so loosely that, according to official documents released under the Freedom of Information Act, anyone who is guilty of "irresponsible expressions of opinion" can be refused entry to the United States. In this climate, the American Civil Liberties Union reports, the government has recently denied, delayed, or revoked visas to a group of seventy-five South Korean farmers and trade unionists opposed to a free-trade agreement; a Marxist Greek academic; a Sri Lankan hip-hop singer, whose lyrics were deemed sympathetic to the Tamil Tigers and the Palestine Liberation Organization; a Bolivian professor of Latin-American history who had been offered a position ...