President George W. Bush's Republicans blocked a Democratic plan to withdraw US combat troops from Iraq by the end of April 2008 to cap a rare round-the-clock US Senate debate this evening.
On a vote of 52-47, backers fell short of the needed 60 to clear a Republican procedural hurdle and move toward passage of the measure opposed by the White House.
Critics called the marathon session, which had featured cots, pillows and toothbrushes, a theatrical stunt by Democrats frustrated by their inability to keep a 2006 campaign vow to end the increasingly unpopular war.
But Democrats described the debate as a bona fide wake up call to pressure wavering Republicans, many of whom are up for re-election next year, to break ranks with Mr Bush and demand a change in course for the war.
Democrats had hoped the showdown vote would be a possible defining moment in the ongoing clash with Mr Bush over the Iraq war. Coinciding with a candlelight vigil by war protesters nearby, the long night's debate drew a majority of senators but appeared to change few minds.
The outcome, though expected, had an air of solemnity as weary senators voted while seated quietly behind their desks.
Senate Democratic leader Harry Reid of Nevada urged support for the measure, which would have begun troop withdrawals within 120 days. "Bring them (US combat troops) home. Let them come home," Mr Reid declared.
"It couldn't be clearer that if you give this president a choice, he will stay hunkered down in Iraq until the end of his failed presidency," Mr Reid said.
Senate Republican leader Mitch McConnell of Kentucky countered that the measure was a poor alternative to current strategy.
"Last night's theatrics accomplished nothing," McConnell said.
"After all the gags and gimmicks, the cold pizza and the empty cots" it was still not clear what the pullout proposal would mean for US strategy, McConnell said.
Senate Armed Services Committee Chairman Carl Levin of Michigan, a chief sponsor of the measure, said setting dates for withdrawal was "the only way that we can force the Iraqi leaders to act" to bolster their own armies and resolve internal differences.
In addition to withdrawing all combat troops by April 30th, 2008, his measure would have kept an unspecified number of noncombat US troops in Iraq to help train Iraqi soldiers, conduct counterterrorism missions and protect US diplomats and facilities.