WASHINGTON -- U.S. Sen. Russ Feingold, the Wisconsin Democrat who chairs a key Senate subcommittee dealing with Constitutional matters, says he will struggle to assure that the response to Tuesday's terrorist attacks on New York and Washington will balance security concerns with respect for the Constitution.

"These are the moments that are the greatest tests of our commitment to Constitutional liberties," says Feingold, who heads the Constitution Subcommittee of the Senate Judiciary Committee. "The worst thing that we could do to reward our enemies is to compromise our commitment to civil liberties."

Feingold says that, for the most part, he was impressed with the initial restraint of members of Congress in the aftermath of deadly terrorist assaults on the World Trade Center in New York and the Pentagon here in Washington. "I have not heard anything that suggests that kind of kneejerk reaction that would put people's freedoms at risk," says the senator. "But I think we have to be alert. We have to make sure that we do not see the sort of suspension of civil liberties that does not make America more secure but that simply divides us."

Feingold's concerns were echoed by veteran defenders of civil liberties on Capitol Hill. U.S. Rep. Lane Evans, D-Ill, a senior House Democrat who has long been one of the most thoughtful defenders of civil liberties in the Congress, said, "In a situation like this, you always have to worry about the Bill of Rights being tossed out the window."

Recalling the internment of Japanese-Americans during World War II and the targeting of Arab-Americans in the immediate aftermath of the 1995 Oklahoma City bombing, Evans said, "We've seen in the past a willingness on the part of many in government to sidestep the Bill of Rights. I'm always concerned, in a moment like this, about gross violations of human rights, especially violations of the rights of immigrants, of people with dark complexions, of people with foreign-sounding names."

American Muslims shared Evans' worries. Imam Hassan Qazwini, religious leader of the Detroit-based Islamic Center of America, expressed concern about threats to Arab-Americans in the aftermath of the attacks. "We are no exception to American society," the Imam said, noting that Muslims in the United States share the sorrow and horror of other Americans in the aftermath of Tuesday's attacks. Hopefully, the Imam said, there will not be a rush to treat Muslims as suspects, rather than citizens.

Evans said he was hopeful that past experience had made Americans more aware of the need to preserve basic freedoms even in the most difficult moments. "We're a much more sophisticated nation. I am hopeful that we will not see pressure for censorship, for limits on information," the congressman said. "The best way to counter terrorism is by making sure that citizens have access to information and that they have the freedom to discuss that information."

Feingold argues that open and free dialogue will be particularly important in coming days, as the U.S. determines how to respond to the terrorist attacks.

"If a foreign power attacks our country, there is no question that we should react," said Feingold, who in the past has raised concerns about U.S. military adventurism abroad. "But to just attack some country because we think it may be responsible for an attack on U.S. soil is wrong," said Feingold. "Obviously, we have to react with a degree of certainty."