Washington ? As senators launched an all-night sleepover Tuesday, Capitol custodians in green work shirts rolled folded cots with flowered mattresses into the Lyndon Baines Johnson room, just steps from the chamber.

Workmen set up sleeping cots in a room off the Senate Chamber on Capitol Hill on Tuesday in Washington as the Senate prepared for an all-night session to debate the war in Iraq.

The cots, which were trucked in from nearby Cheverly, Md., were greeted by a crush of photographers and television cameras, eager to capture the image of a rare, all-night session.

While the mood was almost festive, the occasion was serious as the Senate debated an amendment to begin withdrawing U.S. troops from Iraq in the next 120 days, leaving behind only those soldiers necessary to fight terrorists, train Iraqi soldiers and protect American assets.

Typically, U.S. senators legislate by day and raise campaign funds by night, attending receptions held by special interests throughout the city.

But Democrats said they wanted to draw attention to the war in a way that would convey just how serious they are about ending American combat in Iraq after more than four years there.

“This is not a routine issue,” Sen. Dick Durbin, D-Ill., the assistant Democratic leader, said in an interview. “This is a life-and-death issue and we shouldn’t treat it in a routine way.”

The ostensible reason for the all-night debate was Republican insistence on a procedural hurdle requiring 60 votes before the actual vote on the withdrawal legislation could be taken. That requirement, needed to quash a filibuster, has become increasingly commonplace in the Senate on any matter that’s the least bit controversial.

But it poses a problem for Democrats who can muster a simple majority in favor of re-deploying troops with the help of three Republicans, but not the harder-to-reach 60 votes. Republicans said they would be happy to hold the vote at any time, waiving the lengthy filibuster debate. But Democrats cried foul, insisting on putting lawmakers through their paces, hoping to wear down GOP resistance.

“This is what a filibuster is all about,” said Durbin, who planned to speak from 3 to 4 a.m. “We have sanitized and civilized filibusters so that aging and pampered senators are not inconvenienced.”

Republicans said it was nothing more than cheesy political theater.