In a two-hour interview on Sunday, Mr. Clark, a tall, gaunt figure, still with a Texas drawl after decades living in New York, set out a rationale for defending Mr. Hussein that would face little contest in American law schools. All men, he said, deserved a fair trial, even history's worst criminals. "Suppose Hitler had survived," he said. "It seems to me that it would have been absolutely critical to give him a fair trial, to let him call witnesses and cross-examine the hell out of them." He added, "If you don't do that, historical truth will be distorted."

Mr. Clark, son of a Supreme Court justice appointed by President Harry S. Truman, made his mark in the Johnson years with his role as a Justice Department official in drafting the Voting Rights Act and the Civil Rights Act, liberal landmarks of the age. But for most of the last 40 years, he has steered an unconventional passage of his own. It has been a journey that has taken him on many a far-flung venture abroad, and across America, to embrace some of the era's most notorious figures.

It is a remarkable roll call, the men who have had him at their side at times of confrontation with America and its government: Col. Muammar el-Qaddafi of Libya, Slobodan Milosevic of the former Yugoslavia, Charles Taylor of Liberia; and, at home, fringe figures like the Branch Davidian leader David Koresh, the right-wing gadfly Lyndon LaRouche, and Sheik Omar Abdel Rahman, who is serving a life term in an American jail for his role in the bombing of the World Trade Center in 1993.

Then there is Mr. Hussein. The two men met in Baghdad for the first time during the Persian Gulf war in 1991, and at least four more times during the 1990's, when Mr. Clark opposed the economic sanctions imposed on Iraq after Mr. Hussein's invasion of Kuwait in 1990, and renewed when he failed to comply with United Nations inspector teams searching for unconventional weapons. Now, Mr. Clark is one of three foreigners - the others are a Qatari and a Jordanian - on Mr. Hussein's five-man defense team, and Mr. Clark finds himself explaining, as so often before, how a former Texas liberal finds himself working in support of a man as notorious as Mr. Hussein.

One thing that seems reasonably certain is that Mr. Clark is not in it for the money. In the interview on Sunday - at the Rashid Hotel in Baghdad's heavily fortified international zone, a short bus ride from the bombed-out former Baath Party headquarters that has been remodeled for the trial - Mr. Clark was asked about his fee for representing Mr. Hussein. Mr. Hussein's hidden wealth has been a matter of keen speculation since his son Qusay, on the eve of American troops' sweep into Baghdad in April 2003, sent a flatbed truck to Iraq's central bank to make off with steel trunks containing at least $1 billion in cash.

"Not a penny," said Mr. Clark, who added that he had taken no fee from many of his more contentious clients. What about the air fares on his shuttles between Baghdad and New York, where Mr. Clark lives with his wife, Georgia, in a Greenwich Village condominium? "Economy class," he said, $1,400 for the 13-hour leg from New York to Amman, Jordan, and a 500-mile additional leg to Baghdad. Mr. Clark made the journey twice in the last week, sandwiching legal work in New York between appearances at the Hussein trial. While the air fares have been paid with the Hussein legal team's funds, he said, he was paying for meals and taxi rides himself.