The Senate voted overwhelmingly in favor of an amendment to the military spending bill that sets new limits on how the U.S. military may interrogate detainees it is holding after a series of scandals involving Iraqi and other prisoners.

SENATE CLERK: Mr. McCain, aye --

KWAME HOLMAN: Aware of the president's veto threat, 90 members of the Senate, nevertheless, last night approved an amendment to regulate the custody of battlefield detainees and outlaw their cruel inhuman and degrading treatment.

The size of the margin was due in part to the efforts of three Republicans, all members of the Senate's Armed Services Committee. Arizona's John McCain, a prisoner of war in Vietnam, and the chief sponsor of the amendment; Lindsey Graham of South Carolina who has served as a military lawyer and judge; and the chairman of the committee, Virginia's John Warner.

SEN. JOHN WARNER: At one time when I was privileged to be secretary of the Navy, when the war in Vietnam came to an end, I dealt extensively with the prisoner issue in that tragic era of our history and their families. And I think I have had some insight into this situation, which enables me to give the strongest possible endorsement to this amendment by the senator from Arizona.

KWAME HOLMAN: The senators said it was time to act, that they have heard too many stories of prisoner abuse at Guantanamo Bay, Cuba and had seen enough photographs from Iraq's Abu Ghraib Prison.

SEN. JOHN McCAIN: I've been asked before, where did the brave men I was privileged to serve with in Vietnam draw the strength to resist to the best of their ability the cruelties inflicted on them by our enemies.

Many of my comrades were subjected to very cruel, very inhumane and degrading treatment -- a few of them even unto death. But every one of us, every single one of us knew and took great strength from the belief that we were different from our enemies, that we were better than them, that we, if the roles were reversed, would not disgrace ourselves by committing or countenancing such mistreatment of them.

That faith was indispensable not only to our survival but to our attempts to return home with honor. Many of the men I served with would have preferred death to such dishonor.

KWAME HOLMAN: McCain and his colleagues began their effort back in July when they attached the standardized detention rules to a long list of new military programs contained in Sen. Warner's defense authorization bill.

SEN. LINDSEY GRAHAM: If you know what the rules are about interrogating anybody, come tell me, because I can't figure it out. I've spent 20 years as an Air Force lawyer myself. There's much confusion. And confusion in war is dangerous.

KWAME HOLMAN: Not even a personal plea from Vice President Cheney could deter the three Republicans from their mission. But Majority Leader Bill Frist did, temporarily, by pulling the defense bill off the schedule.

SEN. BILL FRIST: We will proceed to the bill on gun liability.

KWAME HOLMAN: However, McCain saw another opportunity this week when the annual defense spending bill, already six days overdue, was brought to the floor.

But tensions ran high as Appropriations Committee member Ted Stevens fought off Warner's attempt to attach those new programs scuttled in July.

SEN. TED STEVENS: Under those circumstances, I am appalled that the two senators would proceed this way. And I tell the senator from Virginia, our friendship is very close to the brink, very close to the brink, because I believe my job is to get this bill passed and get it passed as a bill we know we can go to conference on and get it done and be ready when we get back.

KWAME HOLMAN: Later in the debate there was another tense exchange when Alabama Republican Jeff Sessions questioned information McCain had received from a Capt. Ian Fishback of the 82nd Airborne who also spoke to the New York Times.

SEN. JEFF SESSIONS: Capt. Fishback said he had seen at least one interrogation where prisoners were being abused. Now I don't know what abused means. I'm a former prosecutor. What does "abused" mean? Did they shake them; did they respond to being spit on by prisoners, as many of our guards are? Did they injury them in some way?

I think if they were beaten he would have said they were beaten. He didn't say that, he used a far more general term that they were abused. And then he goes on to say that he was told about other ill treatment of detainees by his sergeants. Ill treatment, now what is that? He didn't say they were beaten, shot, killed, wounded, tortured -

SEN. JOHN McCAIN: The senator from Alabama's remarks concerning his allegations of abuse and his disparagement of his word and his conduct is unacceptable. Capt. Fishback is a noble, brave young American; he does not deserve to be disparaged on the floor of this Senate by any senator. And the senator from Alabama owes him an abject and deep apology.

SEN. JEFF SESSIONS: The senator from Arizona has asked that I apologize for disparaging Capt. Fishback. I don't believe I did so in any way. Now if something is in error about that -- I quoted simply from the New York Times - I would apologize.

But I also think those in this Senate who have accused the up and down members of the chain of command of the United States Army, the United States Marines, the Department of Defense of being -- promoting policies to abuse prisoners, they ought to think about whether they should apologize. I believe that's false also --

KWAME HOLMAN: Jeff Sessions was one of nine senators to vote against adopting rules for detainee treatment. Ted Stevens argued the rules weren't clearly defined and voted against them too. And since the new rules aren't part of the House spending bill, it's unclear whether they'll survive negotiations between the two chambers.