"We need to step back," said Rep. Barbara Lee (D-Calif.). "We're grieving. We need to step back and think about this so that it doesn't spiral out of control. We have to make sure we don't make any mistakes."

She was walking down a hallway in the Cannon House Office Building. A plainclothes police officer hovered a few steps away, looking very serious. The Capitol Police began guarding Lee on Saturday because of death threats she received after voting against a resolution authorizing President Bush to use military force against anyone associated with last week's terrorist attacks. The resolution passed 98-0 in the Senate and 420-1 in the House. Lee's was the sole dissenting vote.

"In times like this," she said, "you have to have some members saying, 'Let's show some restraint.' "

Led by her police bodyguard, she moved along quickly, slipping into her office and closing the door behind her. Inside, the phone lines had shut down under an onslaught of calls from all over the country -- many of them irate, some of them downright nasty -- and her voice mailbox was too full to take any more messages.

"We've gotten thousands of calls and thousands of e-mails," she said. "People are very emotional. . . . They're frustrated and they're angry."

She's 55, a small woman with short black hair. Normally, she has a bright smile, but these days she looks sad, worried, harried. She is quick to point out that she voted to condemn last week's attacks and to allocate $40 billion to fight terrorism.

"I'm just as American and just as patriotic as anybody else," she insists.

She does not rule out military action, she says, but she voted against the authorization to use force because she opposes giving the president the sole decision on when and where to make war. "I believe we must make sure that Congress upholds its responsibilities and upholds checks and balances. This is a representative democracy and it's our responsibility."

War, she believes, is not the most effective way to fight terrorism. "Military action is a one-dimensional reaction to a multidimensional problem," she says. "We've got to be very deliberative and think through the implications of whatever we do."

This is not the first time Lee has stood alone against war. In 1999, during the crisis in Kosovo, she was the only House member to vote against authorizing President Clinton to bomb Serbia. "I'm not a pacifist," she says, "but I don't believe military action should be the only action we embark on."

Fortunately for Lee, she represents one of the most liberal congressional districts in the United States -- California's 9th, which includes Berkeley and Oakland. It's the district that was represented by another antiwar dissident -- Ronald Dellums -- for nearly 28 years. Lee served as Dellums's chief of staff for a decade before she was elected to the California State Assembly in 1990. When Dellums retired in 1998, she won the election to succeed him, and was reelected last year with 85 percent of the vote.

"I would have voted the same way," says Dellums, now president of Washington-based Healthcare International Management. "We need to think this through and ask, 'Are there better ways to do this?' "

"I agonized over this vote all week," she says. "I searched my conscience. I talked to many people. Ultimately, on some votes, you have to vote the way your conscience dictates."

Her agony was exacerbated by the knowledge that her chief of staff, Sandre Swanson, was mourning the death of his cousin Wanda Green, who was a flight attendant on the hijacked United jet that crashed in Pennsylvania.

"I support her decision," Swanson says. "The principle on which she based her decision was that somebody should stand up and say that only Congress has the power to declare war. . . . People say she was unpatriotic. I think it was very patriotic."

"I admire the courage of Barbara Lee," says Rep. John Lewis (D-Ga.), who spent the 1960s in the front lines of the civil rights movement. "She demonstrated raw courage to stand up and vote the way she did. She stood alone -- one against 420. Several other members wanted to be there also but at the same time, like me, they didn't want to be seen as soft on terrorism."

Lewis voted to authorize military action but, he says, he came close to joining Lee in opposition. "I was probably 99 percent of the way there in my heart and my soul," he says, "but in the end I wanted to send the strongest possible message that we can't let terrorism stand."

Lee's vote is reminiscent of the first woman ever elected to Congress, Jeannette Rankin of Montana, who voted against the nation's entry into World War I and World War II. It also brings to mind Wayne Morse and Ernest Gruening, the two senators who voted against the 1964 Gulf of Tonkin resolution, which gave President Lyndon Johnson the power to wage war in Vietnam.

On the House floor last Friday night, Lee quoted Morse: "I believe that history will record that we have made a grave mistake in subverting and circumventing the Constitution of the United States." She added: "Senator Morse was correct, and I fear we make the same mistake today."

Out in Oakland, Lee's vote is the subject of much debate, some of it heated, says Don Perata, the Democratic state senator who represents Lee's district.

Perata calls Lee's vote "wrongheaded" and he isn't impressed with her explanation of it. "There wasn't a lot of clarity there," he says. "I would have cast a different vote. This is a time for a united front in America, particularly in Congress."

But, he predicts, Lee's vote probably will not affect her chances for reelection.

"The district is overwhelmingly Democratic," he says. "There are probably more people who are to the left of the Democrats than there are Republicans."

Also, he adds: "Barbara is very popular here. She's just a very, very nice woman -- and in this business that counts for a lot."

On Monday, Perata says, California talk radio was abuzz with callers denouncing Lee as a communist.

"I was wincing," he says, "because that's not Barbara. She did not cast that vote because she's unpatriotic. She loves this country and its opportunities as much as anybody."

Meanwhile, back in her office on Capitol Hill, Lee was furiously working the phones, talking to constituents and local media outlets.

"I hope that when I get my message out," she says, "people will understand why I did what I did. Whether they agree with me or not, they'll understand that I want to bring these [terrorists] to justice as much as anybody else does."

She declined to speculate on the effect her vote might have on her popularity. "This was not," she says, "a poll-driven vote."

Rep. Barbara Lee was the only dissenter in the vote giving President Bush war powers.Democrat Barbara Lee, seen here addressing

a group in Oakland

last year, represents California's 9th District, known for

its voters' liberal views.