The Senate voted, 51-46, to OK the conference report’s goal of withdrawing most U.S. troops from Iraq by April 2008. Sen. John McCain (R-Ariz.) missed the vote while on a presidential campaign swing, and Sens. Lindsey Graham (R-S.C.) and Tim Johnson (D-S.D.) were also absent.

“We don’t want a scuffle with the president,” Senate Majority Leader Harry Reid (D-Nev.) told reporters after the vote. “The president has to work with us. He refuses to do that.”

Republican leaders signaled that they could accept certain benchmarks for political progress by the Iraqi government remaining in the post-veto supplemental. Any attempt to link benchmarks to diminishing troop levels, however, is likely to meet with GOP lawmakers’ ire.

“I don’t have a problem with benchmarks and I don’t have a problem with some of the domestic adds” to the war-funding bill, Senate Minority Whip Trent Lott (R-Miss.) said.

Senate Minority Leader Mitch McConnell (R-Ky.) also left the door open for a second supplemental that puts some pressure on the Iraqis: “There are a number of members in my caucus who think benchmarks could be helpful, depending on how they’re crafted.”

While Defense Appropriations Chairman John Murtha (D-Pa.) and his fellow appropriators, including full Appropriations chief David Obey (D-Wis.), asserted that the idea of a shorter-term supplemental is still on the table, McConnell pointed out that such a post-veto plan has few supporters in the Senate.

The timing of both sides’ next move is highly fluid. Reid cited June 1 as a realistic timetable for completing work on a second supplemental, but House Speaker Nancy Pelosi (D-Calif.) promptly replied that the post-veto language could come “sooner.”

Even the time at which Bush will uncap his veto pen is at issue between the parties.

Democrats don’t plan to deliver the bill until late Monday or early Tuesday. That is the fourth anniversary of the president’s ill-conceived appearance on an aircraft carrier in front of a sign that read “Mission Accomplished.”

If Democrats wanted to, they could light a fire under their staff to get the bill delivered by the end of this week, say Republican officials who handled the process under GOP rule. That way, Bush could put a weekend between his high-profile veto and the speech anniversary.

Since the speech, in which the president announced the end of major combat operations, the instability in Iraq has grown into an insurgency, thousands more troops have been killed and the country has plunged into what many say is a civil war. The “Mission Accomplished” sign has become, for Bush’s political adversaries, a symbol of the president’s overconfidence and misunderstanding of the conflict.           

Republicans say there’s no accident to the timing and accuse Democrats of playing politics.

“If Democrats are truly interested in forward progress and not just partisan gamesmanship, they will send this measure to the President for his prompt veto today,” House Minority Leader John Boehner (R-Ohio) said in a statement. “To delay this veto is to delay the funding of our men and women fighting in harm’s way.”       

Democrats say they made no effort to put the bill on Bush’s desk on the anniversary of the speech.

“That has never come up in our leadership meetings,” said Rep. John Larson (D-Conn.), vice chairman of the Democratic Caucus. But he added, “Everyone’s aware of the anniversary. It will provide a great talking point about what the president has gotten by his own arrogance and hubris.”    

Murtha said there are logistical reasons why the bill can’t go to the White House until next month.

“It can’t be delivered until Tuesday because of the funeral,” Murtha said, referring to services for Rep. Juanita Millender-McDonald (D-Calif.), who died Sunday. The House will be out Monday for her funeral.           

After a bill is passed by both chambers, staffers in the office of the clerk in the chamber where the bill originated — the House, in this case — carefully go over the bill to ensure that what is being sent to the president is what was passed on the House floor.

When the clerks of both chambers have signed off on it, the House Speaker and Senate president pro tempore must sign off on sending it to the president. They certify as constitutional officers that it is correct and that the right version is going to the White House.