As Republican Senators prepare for a possible September standoff with Democrats over their choice for the 5th U.S. Circuit Court of Appeals, the remaining members of the bipartisan “Gang of 14” say they may have to come together to help referee the fight.

Senators in both parties said last week that it is premature to map out exactly how Leslie Southwick’s controversial nomination to the federal bench will play out when Congress returns to work next month. But Democrats and Republicans alike said liberal Democrats might look to try to filibuster Southwick’s nomination — a move that could force the Senate to once again play host to a divisive battle over President Bush’s picks for the court.

“I hope not, but you have to expect that might happen given the manner with which he came out of committee,” Sen. Ben Nelson (D-Neb.) said of a filibuster.

Nelson, who has said he favors Southwick’s nomination, is one of the 12 remaining Senators in the bipartisan Gang of 14, which teamed up to avert the last major showdown in the Senate over judicial nominations. The gang largely has been inactive in recent months, but its organizers have long insisted that they may reunite if and when the Senate faces a judicial battle once again.

“The structure allows for that possibility,” Nelson said. “It may be a different group, but that’s a strong possibility.”

“I wouldn’t rule it out,” added Sen. Mark Pryor (Ark.), another Democrat in the gang. “But it’s too early to tell.”

It’s unclear what specific role the Gang of 14 would play if any at all, but the group previously kept the Senate in business when then-Majority Leader Bill Frist (R-Tenn.) threatened to impose the “nuclear option” to avert Democratic filibusters over Bush’s stalled judicial nominations. The gang brokered a deal under which it would support up-or-down votes on certain controversial nominees in exchange for keeping the right of the minority filibuster intact.

Sen. Olympia Snowe (R-Maine) said she believes Senators on both sides of the aisle will be investing their time in the coming weeks reviewing Southwick’s record and analyzing the issues surrounding his nomination. She agreed, however, that those moderate Senators who helped avoid a standoff in the previous Congress might have to be called to duty again.

“Hopefully we’ll work through it,” Snowe said.

Southwick’s nomination has been embedded in controversy from the get-go. With the support of nine Republicans and just one Democrat, Sen. Dianne Feinstein (Calif.), the Judiciary Committee voted 10-9 on Thursday to send his confirmation to the full Senate. Majority Leader Harry Reid (D-Nev.) has said he plans to bring the nomination up sometime after Labor Day, but Reid — along with scores of other Democrats — remains strongly against Southwick’s installment on the 5th Circuit given his civil and human rights record.

Still, those opposing Democrats weren’t ready late last week to handicap the outcome, arguing it was far too soon to predict Senators’ floor strategy.

“I just don’t know,” said Judiciary Chairman Patrick Leahy (D-Vt.), who opposed Southwick’s advancement to the Senate. “That’s a question for Harry Reid.”

“Nobody knows,” said Democratic Senatorial Campaign Committee Chairman Charles Schumer (N.Y.), another Judiciary Democrat who voted against Southwick. “It’s much too early to tell.”

Early or not, both parties will experience intense pressure from constituency groups to vote a certain way, and Democrats already are anticipating a heavy push on their side to try to block Southwick on the floor. Democrats also must consider several factors, including whether they can uphold a filibuster, are willing to devote critical September floor time to fighting judges and the fact that some of their own Senators support the nomination.

And as one senior Democratic aide said, “It’s significantly more difficult to sustain a filibuster with a Democrat on record in support of Judge Southwick.”

But GOP Senators who are fighting on Southwick’s behalf are hoping Democrats think long and hard about tripping up his confirmation, especially after one of their most respected colleagues, Feinstein, voted in favor of his nomination. That, coupled with the risk associated with a protracted floor fight riddled with political implications, should be reason enough for a straight up-or-down vote, Republicans argued.

“It would be open warfare if they try to filibuster this guy,” Judiciary ranking member Arlen Specter (R-Pa.) said.

Sen. Thad Cochran (R-Miss.), one of Southwick’s most prominent backers, said he will spend the coming weeks answering his colleagues’ questions and continuing to make a case that Southwick is a well-qualified candidate with an exemplary record. Though he doesn’t believe a filibuster by Democrats is likely, Cochran also refused to game out what will happen once Southwick’s nomination comes before the full Senate.

“Having come to this point, I’m not making any predictions,” Cochran said. “There’s not a formula for getting something approved in the Senate.”