Senate Majority Leader Harry Reid (D-Nev.), a veteran tactician, might have trouble this week shepherding a $250 billion war supplemental that satisfies the domestic spending desires of his caucus while sidestepping a filibuster and veto.

Complicating his task, House Republicans last week boycotted the vote on war funding, a maneuver that killed the measure with the help of anti-war Democrats. Plus, a Senate Appropriations Committee markup turned into a spending spree for Democrats and Republicans alike.

“It’s all very confusing,” said one Senate Democratic leadership aide. “It’s a little more fluid than usual. … The question is what we’re going to be able to negotiate.”

The aide said the confusion was caused “in large part because of the disarray in the House Republican ranks when they voted against the troops.”

As of Friday, Senate Democrats said they have only a rudimentary plan for how to salvage the war funding portion of the bill.

They have decided to combine their $169 billion amendment to fund war operations into a Senate Appropriations amendment to restrict troop deployments. That would be offered to a House amendment that also seeks to hasten the end of U.S. combat operations in Iraq.

Originally, the House was expected to send the bill over in three separate amendments: war funding, domestic spending and restrictions on war strategy. But now the Senate will receive two: the restrictions on the war and the domestic spending components.

Senate Democratic aides said they probably would not settle on a strategy for each step of the process until after debate has begun, either Tuesday or Wednesday.

The first part up for debate will be the House’s domestic spending amendment, which is narrowly focused on providing education funding for war veterans and extending unemployment benefits. Senate Democrats will attempt to broaden that package by more than $10 billion, using the Senate Appropriations panel’s bill as an amendment.

Because Senate Republicans are likely to block adoption of the Senate’s domestic spending measure, it is unclear if Democrats will seek to offer some spending separately. “If it doesn’t get 60 votes, there will be some negotiation,” said the Senate Democratic leadership aide. “Once we get on the first [House] amendment, we’ll be on that for a while.”

Additionally, Senate Republicans feel confident that they can kill a House provision levying a tax on millionaires to pay for GI bill education benefits. What remains to be seen is whether Republicans also will attempt to strip the GI bill from the measure. Many Senate Republicans have rallied around a less costly version sponsored by presumptive Republican presidential nominee Sen. John McCain (Ariz.), but have privately expressed concerns about voting against the Democratic version.

“We really think we’ve got a shot at getting 60” votes on the GI bill, a senior Senate Democratic aide said. Sixty votes are needed to prevent a filibuster, and every vote on the supplemental will likely be subject to that threshold.

With or without the “millionaire tax,” President Bush has threatened to veto the supplemental over the GI bill, which he has said is too expensive.

Senate Republicans said they were uncertain about their strategy for the floor debate, given that they will likely have to take several politically difficult votes on the GI bill.

“We’re going to be reactive,” said one senior Senate Republican aide. This aide cautioned that because Reid has the power to block Republicans from offering amendments, they must wait to see what they will offer. Some Republicans want to jettison the entire spending package.

“Obviously, there’s an interest in getting a vote on a ‘clean’ supplemental,” said the aide. “But there could be other amendments as well.”

House Democrats last week already were acknowledging that negotiations over the supplemental would drag on past the Memorial Day recess, while House Republicans started to beat on Democrats for delaying funding for the troops even as they refused to hold committee markups or allow any meaningful Republican input.

In a shocking floor protest last week, 132 House Republicans voted present, and the war funding amendment died 141-149 with most Democrats voting against it.

Although House Republicans still would have the power to block war funding in protest over additional spending when the bill returns from the Senate, most are not expected to do so on a final vote. Several Republicans who voted present last week noted that it didn’t actually affect the timing of the war funding because the Senate was sure to send a bill back to the House with changes. If Republicans blocked that bill, they would open themselves up to charges from Democrats that they, not Democrats, are delaying funding for the troops.

The millionaire tax is part of the House bill because Blue Dog Democrats insisted on an offset for the GI bill — an offset that is not likely to survive the Senate. So Blue Dogs probably will face a choice: They can vote for a war and GI/domestic aid package that isn’t paid for — and try and pin the blame on Republicans, the Senate and the president for forcing a violation of pay-as-you-go rules — or they can vote against funding for the troops, something they don’t want to do.

In the end, most Blue Dogs probably will back the final package, as will many House Republicans.

Members of the House Out of Iraq Caucus, who enjoyed a momentary victory last week, could be left with little to crow about, as the 110th Congress will have passed a bill that keeps the war going well into 2009 without meaningful restrictions.

House Republicans continue to demand that Democrats acquiesce to a “clean” war supplemental as requested by President Bush.

“The expectation and the hope is that the Democrats will move a clean troop funding bill so that the president can sign it before Memorial Day, which our military has told us is the deadline,” said Michael Steel, spokesman for House Minority Leader John Boehner (R-Ohio). “Is there not some sense of shame that they haven’t acted on it by the time the military set?”