If the more than two dozen House Republicans who voted against the earlier Patriot Act extensions maintain their opposition, GOP leaders will need the support of Democrats to pass next week’s bill. (By Jacquelyn Martin/Associated Press)

The other half – rounding up enough votes next week to pass the measure before both chambers recess for Memorial Day weekend – is likely to be the tougher fight.

The fact that the Patriot Act is one of those issues on which views are not neatly split along party lines makes it somewhat hard to predict what will happen when the legislation reaches the floor of either chamber, and unexpected alliances and splits are often the case.

The White House and most Republicans, for instance, have favored a permanent extension of the three expiring Patriot Act provisions; Attorney General Eric Holder testified before the House Judiciary Committee this month that the administration would like to see the provisions extended “for as long as we possibly can.”

But House Democratic leaders, with the exceptions of Minority Whip Steny Hoyer (Md.) and Rep. Chris Van Hollen (Md.), all voted “no” on extending the Patriot Act provisions in February, and overall, House Democratic opponents of the legislation outnumbered supporters by nearly two to one.

House Republicans, meanwhile, have their own problem to worry about – the more than two dozen members who voted against the extension this year. House Republicans have a 22-seat majority in the House, meaning if the members who voted against the earlier Patriot Act extensions maintain their opposition, Republican leaders will need the support of Democrats to pass the bill.

That means that there is likely to be plenty of pressure from above on the 26 House Republicans who voted against the earlier extension.

(Remember that when House Republicans first tried to fast-track the measure this year, the move backfired as the extension unexpectedly garnered less than the two-thirds needed for passage; at the time, Democrats blamed Republicans for miscalculating, while Republicans argued that Democrats were the ones who had dealt a fatal blow to the measure.)

In the Senate as well, bipartisan support will probably be needed to pass the measure, just as it was when the upper chamber passed the last extension in February. On that vote, 40 members of the Democratic caucus backed the extension while 10 opposed it; on the Republican side, 45 members supported the measure and only two – tea party-backed Sens. Rand Paul (R-Ky.) and Mike Lee (R-Utah) – voted no.

Timing is also a key factor, as leaders of both parties have little room for error next week. Senate Majority Leader Harry Reid (D-Nev.) announced Thursday that the Senate will vote to end debate on S. 1038, the extension of the three key Patriot Act provisions, at 5 p.m. next Monday.

That sets up a final passage vote in the Senate for next Wednesday. The measure would then head over to the House, which would have to pass the bill before heading out of town Thursday to prevent the Patriot Act provisions from expiring.

The measure extending the provisions is set to expire May 27.

It’s worth noting that while Reid had pledged to devote a full week of debate on the Senate floor to renewing the Patriot Act provisions, that doesn’t look likely to happen.

In fact, that only serves to underscore that one of the more interesting aspects of the Patriot Act debate is that while the measure — like a raising of the debt ceiling — is must-pass legislation, neither party’s leadership has focused much energy on the issue.

Since each party needs the other’s support for the measure to pass, the same opportunity for brinksmanship and leverage-wielding exists as it does in the debt-limit debate – but perhaps because counterterrorism surveillance doesn’t rank as highly among most voters’ concerns as it used to, and the economy remains Americans’ top priority, neither party has sought to exercise its political muscle on the issue.

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