WASHINGTON (CNN) -- Senate Democratic leaders are revising proposals to end the Iraq war in hopes that a compromise with wavering Republicans can be found, Democratic leadership sources said Friday.
Sens. Carl Levin, D- Michigan, right, and Jack Reed, D-Rhode Island, confer before a hearing last week.
Democrats want to leverage Republican discontent with the 21,500-troop withdrawal announced by President Bush on Thursday to swing GOP votes behind a Democratic pullout plan.
Democratic sources say about a half-dozen proposals will be up for debate when the Senate takes up the defense authorization bill Monday. Debate could begin midweek, they say.
Senate Democrats need 60 votes to avoid a Republican filibuster and get any plan to a vote. It would take 67 votes to override a presidential veto.
The Iraq plan closest to those numbers in the last round of voting was from from Sen. Jim Webb, D-Virginia. His proposal would mandate enough troop rest between deployments to force a reduction of forces in Iraq.
It received 56 votes the last time it came before the Senate.
"This has the advantage of being doable," one source said.
Republican Sen. Gordon Smith of Oregon, who wants a timeline and deadline for troop withdrawal like Democrats, said the troop-rest measure "may be a backdoor way of doing the same thing. ... It would have the obvious effect of reducing numbers."
Republican leadership sources say Webb's plan, which the Senate would attach to a defense authorization bill, wouldn't get a veto-proof majority in the House of Representatives.
But if it did get the Senate's approval, it could make some war-weary House Republicans more inclined to vote for it.
Democratic sources said Senate leaders are looking for votes off a list of 11 Republican senators who have been critical "in one form or another" of Bush's strategy in Iraq. Watch an explanation of Bush's plan for troop cuts »
But one source admitted, with the exceptions of Sen. Chuck Hagel, R-Nebraska, and Smith, "We still don't have any Republicans making a clean break with the president yet."
Senate GOP leader Mitch McConnell of Kentucky said whatever compromise Democrats come up with won't include an Iraq withdrawal deadline.
"I'm very optimistic that the things the Democrats have been trying to achieve for the last six months, which is an arbitrary withdrawal date, a retreat date, in effect a memo to our enemies to let them know when we're going to give up, is not going to pass the Senate next week," McConnell said.
But he did allude to other compromise measures that might be offered
"I do know for a fact that many senators are saying privately ... that the end game is some kind of troop deployment by the United States in the region -- maybe it will be in Iraq, maybe not -- to give us the maximum opportunity to prevent attacks on the homeland, that is attacks here in the United States against innocent civilians," McConnell said.
Sen. Carl Levin, D-Michigan, chairman of the Armed Services Committee, is taking the lead in revising the Democrats Iraq proposal in a way that may be able to garner more GOP votes, sources said. See other possible Iraq legislation »
Democratic sources said Levin is working with Sen. John Warner, R-Virginia, who has announced he's retiring in January 2009. Warner has said troop withdrawals in Iraq should begin by Christmas.
Another Republican who might be swayed to a Democratic plan is Sen. Lamar Alexander of Tennessee, who criticized the plan Bush laid out Thursday.
"He didn't go as far along that path as our country could and should go and still honorably finish the job in Iraq," Alexander said.
But Democratic leaders face the prospect that any compromise with Republicans might alienate the party's liberal wing, which favors a deadline to pull combat troops from Iraq.
Sen. Chris Dodd, D-Connecticut, a presidential candidate, flatly rejected anything short of a deadline. "I cannot and will not support any measure that does not have a firm and enforceable deadline to complete the redeployment of combat troops from Iraq," Dodd said. "Rather than picking up votes, by removing the deadline to get our troops out of Iraq you have lost this Democrat's vote."
Sen. Russ Feingold, D-Wisconsin, said he intends to push for a vote next week on his proposal to redeploy our troops from Iraq to "focus on the global fight against al Qaeda." E-mail to a friend
CNN's Dana Bash, Candy Crowley and Deirdre Walsh contributed to this report.