The Senate gridlocked on the Iraq war in a sharply worded showdown on Saturday as Republicans foiled a Democratic attempt to rebuke President George W. Bush over his deployment of 21,500 additional combat troops. The vote was 56-34. That was six short of the 60 needed to advance the measure, which is identical to a nonbinding resolution that Democrats pushed through the House on Friday. "The Senate, on behalf of the American people, must make it clear to the commander in chief that he no longer has a rubber stamp in Iraq," said Democratic Majority Leader Harry Reid in the final moments before the vote. Republicans blasted him and the Democratic leadership for refusing to allow a vote on an alternative that ruled out any reduction in money for troops in the field. "A vote in support of the troops that is silent on the question of funds is an attempt to have it both ways," said Sen. Mitch McConnell, the Republican leader. "So we are asking for an honest and open debate." The vote marked the second time this winter that Senate Republicans have blocked action on nonbinding measures critical of the president's war policies. This time, however, there were signs of restlessness within the Republican Party. Seven Republicans broke with their leadership, compared with only two on the previous test vote. Also this time, the maneuvering concerned a nonbinding measure that disapproved of Bush's decision to deploy the additional troops and pledged to support and protect the troops. The vote in the House on Friday was 246-182, with 17 Republicans breaking ranks to support the measure and two Democrats voting in opposition. Saturday's debate and vote occurred in an intensely political environment, both in and out of the Capitol. The unusual weekend session sent presidential contenders in both parties scrambling to make the vote. One of them, Democratic Sen. Hillary Rodham Clinton, squeezed in a morning appearance in New Hampshire, where she told one audience, "We have to end this war and we can't do it without Republican votes." Polls show strong public opposition to the war, which as killed more than 3,100 US troops. Democrats seemed eager to force Republicans into votes that might prove politically troublesome. "They are torn between their president's policy and the wishes of the constituents, but vote they must," said Sen. Charles Schumer, head of the Senate Democrats' campaign committee.