"Drawdowns must be based on conditions in country, not an arbitrary deadline rooted in our domestic politics," Sen. John McCain, R-Ariz., said, deriding Democratic calls for redeployments.
Sen. Hillary Rodham Clinton, D-N.Y., countered by saying, "It is time to choose what is more important, a strategy to win in Iraq or a strategy for Republicans to win elections here at home." She accused Republicans in charge of Congress of "blindly following" President Bush.
In highly partisan speeches, Republicans and Democrats squared off over Democratic calls to start redeploying U.S. troops from Iraq this year.
Republicans opposed any timeline. They said it would risk all-out civil war and cripple the Iraqi government just as democracy is taking hold.
"Withdrawing our forces prior to the Iraqis being able to defend themselves would encourage terrorism, embolden Al Qaeda and threaten American security," said Sen. John Warner, R-Va.
Added Sen. John Cornyn, R-Texas: "The policy of retreat and defeatism, and simply giving up, is not one that serves our nation well."
Democrats contended that Bush has failed to articulate a plan for the way ahead in Iraq. They said it is time for troops to start coming home and for Congress to send a clear signal that the U.S. presence is not indefinite.
"We can't go on with an open-ended commitment," said Sen. John Kerry, D-Mass. Sen. Edward M. Kennedy, D-Mass., said, "Staying the course is not an acceptable strategy when the course is a failed course."
With some Democrats saying the decision to go to war was a mistake, Sen. Rick Santorum, R-Pa., and House Intelligence Chairman Peter Hoekstra, R-Mich., tried to dispel arguments by Democratic lawmakers that no weapons of mass destruction were found in Iraq.
Santorum and Hoekstra released a newly declassified military intelligence report that said coalition forces have found 500 munitions in Iraq that contained degraded sarin or mustard nerve agents, produced before the 1991 Gulf War.
But a defense official, who spoke on condition of anonymity, said the weapons were not considered likely to be dangerous because of their age. Also, Democrats said a lengthy 2005 report from the top U.S. weapons inspector contemplated that such munitions would be found.
The Bush administration says U.S. troops will stay in Iraq until Iraqi security forces can defend the country against a lethal insurgency that rose up after the U.S.-led invasion in 2003 that toppled dictator Saddam Hussein.
Republicans relished the daylong debate. It highlighted divisions in the Democratic Party little more than four months before the elections and as the GOP is trying to overcome polls showing that the public favors a power shift to Democrats.
"We're very happy to have this," said Sen. Mitch McConnell of Kentucky, the second-ranking Senate Republican. "It's been interesting to watch the Democrats debate among themselves."
Democrats tried to shift attention from differences in their party even though the debate was prompted by two separate Democratic proposals on the fate of U.S. troops. Votes on both are expected by week's end.
Republicans opted not to offer their own alternative. Instead, they chose to make their position clear with what are expected to be nearly unanimous GOP votes against the Democratic proposals.
One of those proposals, sponsored by Kerry and Sen. Russ Feingold of Wisconsin, would require that the administration withdraw all combat troops from Iraq by July 1, 2007, with redeployments beginning this year.
The other proposal — which Senate Democratic leader Harry Reid and most of his rank-and-file support — would call for the administration to begin "a phased redeployment of U.S. forces" by Dec. 31. The nonbinding resolution would not set a deadline of when all forces must be withdrawn.
Sensitive to talk of a divided party, Reid's office circulated a sheet of paper with the headline, "The Bush Republican Plan on Iraq." It was blank except for the title.
The office also floated a memo from a Democratic pollster suggesting that Republicans are going to pay a price in November for standing with the president's war policies.
"A majority of Americans would like to see a deadline to withdraw our forces from Iraq," said Sen. Jack Reed, D-R.I. "They are terribly concerned and they're looking for leadership."
Republicans dismissed the idea that voters would punish the GOP on Election Day by ousting them from power.
"I'm sure they wish — and we all wish — this could end more quickly but Congress trying to micromanage the war is not going to bring that about," McConnell said.
Democrats played down concerns, voiced privately by some party strategists, that the Kerry-Feingold call for a "hard-and-fast" deadline is hindering Democratic efforts to project a unified position on Iraq for the fall.
"The whole focus is going to be on how George Bush got us into the war and how he gets us out," Sen. Chuck Schumer of New York, the chairman of the Senate Democrats' campaign committee.
Still, that did not explain why Democratic leaders spent more than a week trying to write a "consensus" proposal. They hoped it would persuade Kerry and Feingold to drop their own, which would set a "date certain" for ending the U.S. combat mission.
In the end, the two potential 2008 Democratic presidential candidates were not swayed.
As a result, two votes are planned — both set up by Democrats and both likely to give Republicans ammunition just in time for campaign season.