Even with the Medicare conference report potentially still weeks away from hitting the floor, House Republican leaders have already begun strategizing for what is likely to be an extraordinarily close final vote.

House and Senate conferees continue to huddle over the details of the prescription drug measure, making it hard for leaders to know what exactly they’ll have to work with. But top Republicans have nonetheless begun mapping out a path to passage, identifying which Members will need coaxing and which issues will make it toughest to build even a bare-majority vote.

“We’re looking at a 218 strategy, not a 300-plus,” said a GOP leadership aide, referencing the number of “aye” ballots needed if everyone were to vote.

That’s the same strategy Republicans employed on the House’s original version of the bill, which passed in June by a 216-215 margin after the vote was held open for nearly an hour. GOP leaders expect the next floor fight to be even tougher, given that the conference report will necessarily include some provisions supported by the Senate that House Members — particularly conservatives — will find unpalatable.

House Republicans are also counting on an assist from President Bush, who has made clear that he sees the Medicare bill as one of the top domestic priorities of his administration. The president conveyed that message to the conferees when they visited the White House last week, imploring them to deliver a bill to his desk as soon as possible.

At the same time, lawmakers have a message of their own for Bush: The administration has to get its hands dirty if it wants a bill.

“It’s imperative that the White House be engaged in this thing,” said Rep. Mike Rogers (R-Mich.), the Deputy Whip for coalitions.

Congressional Republicans, particularly in the House, have occasionally grumbled that this administration regularly likes to take credit for legislative successes but is rarely willing to get involved in tough floor fights and expend political capital.

But House vote-counters will likely need the White House’s help this time, especially when the inevitable, last-minute bartering sessions take place on the floor.

During the June vote, Republican leaders had to make some well-publicized promises to secure passage, most notably a commitment to Missouri GOP Rep. Jo Ann Emerson that there would be a vote on drug reimportation legislation. Several more deals were cut in private, some with lawmakers who were generally supportive of the bill but still held out in order to extract concessions.

Only nine Democrats voted in favor of that measure — fewer than either side expected — and Republicans cannot count on getting more support from the other side of the aisle this time around.

More importantly, 19 Republicans voted no, and many of those lawmakers will be the subject of an early and intense lobbying campaign from the leadership.

Several Members who voted aye in June have already made clear to the leadership what they will and will not support in a conference report. Three weeks ago, a group of conservatives sent a letter to Speaker Dennis Hastert (R-Ill.) laying out their criteria for an acceptable final bill.

To keep those and other Members informed, the leadership has been closely monitoring the on-again, off-again progress of the current House-Senate negotiations and passing on regular updates. Leaders have been emphasizing to conservatives that the bill is not just an expensive new entitlement program but also represents a rare opportunity to reform Medicare.

“This is mostly so Members are aware step-by-step of what is happening in the conference so they’re not just being presented with a final product,” explained a Republican leadership aide.

House Majority Whip Roy Blunt (R-Mo.) has been having daily meetings with lawmakers during which he has sounded many of them out about Medicare. The subject has also been a topic of discussion during Whip meetings.

As the final contours of the bill become clearer, so too will the roles of the various vote-counters. Some leaders will focus on recalcitrant conservatives, and others will ride the moderates. Individual Deputy Majority Whips will take charge of each potentially divisive issue while committee chairmen will be tasked with rounding up their own panel members.

“There’s a whole bunch of cylinders, and each cylinder presents a separate problem in this Medicare bill,” said Rogers.

“Everyone is going after one of those cylinders and trying to massage to it to the point where everyone is happy.

“We’re going to do this in small increments. This is, since I’ve been here, one of the toughest ones I’ve seen, because there are so many different pressure points.”