By DAVID ESPO

The Senate gridlocked on the Iraq war in a sharply worded showdown yesterday as Republicans foiled a Democratic bid to repudiate President Bush's deployment of 21,500 additional combat troops.

The 56-34 vote fell four short of the 60 needed to advance a nonbinding measure identical to what the House passed Friday.

Democrats swiftly claimed victory anyway. "A majority of the United States Senate is against the escalation in Iraq," said Majority Leader Harry Reid of Nevada. "As for the Republicans who chose once again to block further debate and protect President Bush, the American people now know they support the escalation" in troops.

Republicans blasted the Democratic leadership for refusing to allow a vote on an alternative that ruled out any reduction in money for troops in the field.

"There is no place for chicanery at a time of war," said Senate GOP leader Mitch McConnell of Kentucky. "Even some of the president's most strident opponents know that. They know that the only vote that truly matters in a vote on whether to fund the troops."

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 GOP ranks.

Seven Republicans broke with their leadership - including five whose term ends with the next election - compared with only two on the previous test vote.

Yesterday's maneuvering 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 roll call.

One of them, Democratic Sen. Hillary Rodham Clinton of New York, 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."

Nine Republicans skipped the Senate session, calculating that because they support Bush's policies, their votes would not affect the outcome of the vote.

Among them were Sen. John McCain of Arizona, a presidential hopeful who campaigned in Iowa. In addition, at least two Republican lawmakers had left on an official trip to Iraq to check progress on the war.

The nonbinding measure disapproved of Bush's decision to deploy more troops, and pledged to support and protect the troops in the field.

Even before the House acted, Bush had made it clear that congressional opposition would not deter him from proceeding with the deployment of another 21,500 troops, designed primarily to quell sectarian violence in heavily populated Baghdad.

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