Despite falling well short of the votes needed to pass his proposal to begin the withdrawal of U.S. forces from Iraq within a year, Senate Majority Leader Harry Reid (D-Nev.) is expected to raise the issue again next week as part of the supplemental war spending bill, although it remains to be seen what form that Iraq provision will take, leadership aides said Friday.

But if Thursday’s vote on Iraq were the first test, Senate Republican leaders are feeling optimistic the supplemental will play out similarly. Senior GOP sources suggested late last week that the vote on the Reid withdrawal resolution sent a symbolic, albeit forceful, message to Democratic leaders that they have an equally tough road ahead tying any deadlines to the spending bill.

“I think it makes clear that Reid’s language is dead in the water,” said a senior Republican Senate aide.

Nevertheless, Democrats said that at this point they are less concerned with the actual vote counts than with the public pressure these votes will put on vulnerable Republican incumbents who will be on record voting repeatedly against ending the war.

“Of course they like to believe their Members aren’t going to have to take difficult votes” in the future, a senior Democratic leadership aide said Friday. But this aide warned that it would be “naive to believe that they won’t have to make hard choices when it comes to Iraq on the supplemental.”

Although the aide declined to discuss what specific language Reid is expected to attempt to attach to the bill, aides for Reid and Appropriations Chairman Sen. Robert Byrd (D-W.Va.) met Friday to discuss the issue and Democrats have decided to force another vote on the issue.

According to Democratic aides, beginning midweek Reid and other Democrats will pivot from mesaging on the budget and the U.S. attorneys controversy back to Iraq and the supplemental, building pressure on Republicans with an eye toward a vote late next week.

Democrats said that while this latest proposal may be defeated in the end, Reid is committed to bringing up the issue over and over again to build a record of Republicans backing an administration that Democrats hope to continue to paint as ethically challenged — and use that against Members up next year.

“Ask [New Hampshire Sen.] John Sununu, ask [Maine Sen.] Susan Collins, ask [Minn. Sen.] Norm Coleman how many times they want to vote [with Bush] and explain it to their constituents,” the Democratic leadership aide said.

But Republicans said they believe Thursday’s vote against Reid’s bill was a clear indication of where the Senate stands on the issue. A second GOP leadership aide said Republicans considered last week’s vote to be the real test for what’s ahead in the Senate, saying the outcome was “as much about the supplemental as it was about the Reid resolution.”

This staffer added that most GOP Senators decided they could oppose the Reid proposal after weeks of positive media reports, which portrayed the Democrats as divided and unsure of how to proceed. Plus, many Republicans felt that while the public largely opposes the troop surge, there is a lot of uncertainty about setting specific dates for withdrawal.

“Seeing that steady stream of mainstream coverage gave our guys a little courage,” the leadership staffer said.

The GOP confidence comes on the heels of what leaders view as one of their first major victories as the minority in the Senate — success that came after weeks of behind-the-scenes negotiations to shore up Republican unity and pick off enough Democrats to block support of the binding Iraq resolution crafted by Reid.

In the end, 50 Senators, including Democratic Sens. Ben Nelson (Neb.) and Mark Pryor (Ark.) and Independent Democratic Sen. Joe Lieberman (Conn.), joined together to defeat the withdrawal timeline. One Republican, Sen. Gordon Smith (Ore.), sided with 47 Democrats in supporting it.

That count didn’t occur in a vacuum, Republican leadership sources said. The top GOP vote-counter, Senate Minority Whip Trent Lott (Miss.), set several goals for the showdown, beginning with the objective of blocking Reid from even capturing a simple majority for his resolution.

“Even though they needed 60, [Lott] didn’t want them to get a majority,” said the senior GOP Senate aide. “The goal was to keep it below 50.

“So, instead of having a bipartisan majority rebuking the president, what you saw [last week] was a partisan minority,” the aide added. Lott, along with Minority Leader Mitch McConnell (Ky.), went into the vote expecting to get at least 49 votes against Reid’s resolution, but were hoping to top the 50-vote mark with a few Democrats on board, sources said. Lott honed in on some of those Democrats who didn’t serve as co-sponsors to the Reid measure, which in addition to Lieberman and Pryor, included Sen. Ken Salazar (Colo.), one of the final holdouts who ultimately sided with Reid.

“Lott was cognizant of that list and worked off that list,” said the Senate GOP aide.

Admittedly, one of the biggest challenges for Republicans was containing possible defections by their moderates who, on a previous procedural vote, joined with the Democrats to advance the debate on President Bush’s proposed troop increase. That February vote won the support of seven GOP Senators.

At Thursday’s vote, however, just one of those Republicans — Smith — deserted the Republican Conference come vote time.