WASHINGTON — The Senate yesterday handily defeated a measure to effectively end most American combat operations in Iraq by next April, but the 29 senators who voted for the amendment represented the highest number yet that have united behind a proposal to force President Bush to bring home American troops.

The plan by Senator Feingold, a Democrat of Wisconsin, and Majority Leader Reid, a Democrat of Nevada, did not garner nearly enough votes to pass. Sixty-seven senators — 47 Republicans, 19 Democrats, and one independent — opposed the proposal.

Their amendment won the votes of 28 Democrats and one independent. But support for the Feingold-Reid measure — which followed a similar House vote last week — provided another indication of how public pressure to end the war has pushed congressional Democrats to embrace once politically taboo plans to challenge Mr. Bush’s management of the war.

“It is clear that change is in the air,” Senator Durbin, a Democrat of Illinois, said after the vote. “Our resolutions have not passed, but they will pass.”

Among the measure’s supporters were all four Democratic Senate leaders, as well as the four Democratic senators running for president: Senator Biden of Delaware, Senator Clinton, Senator Dodd of Connecticut, and Senator Obama of Illinois. The Feingold-Reid plan introduced last month would cut off funding at the end of March for all but a limited range of military operations, which include protecting American personnel, training Iraqi forces, and conducting limited counterterrorism operations.

“Congress cannot wait for the president to change course,” Mr. Feingold said. “As long as the president’s Iraq policy goes unchecked, our courageous troops will continue to put their lives on the line unnecessarily, our constituents will continue to pour billions of dollars into this war, our military readiness will continue to erode, and our ability to confront and defeat Al Qaeda will be jeopardized,” he said on the Senate floor.

Yesterday’s Senate vote, during debate of a water projects bill, was a symbolic exercise orchestrated by Senate leaders who agreed to consider four Iraq-related measures before House and Senate negotiators begin working on an emergency war spending bill for the wars in Iraq and Afghanistan.

Mr. Bush vetoed an earlier version of the spending bill because it contained a timeline for withdrawing American forces, including a nonbinding goal of completing the withdrawal by next April. Congressional Democrats hope to send the president a new version of the spending bill by the end of next week.