Despite commanding more than a filibuster-proof majority in support of a class-action reform bill, Senate Republicans still have a lot of wrangling to do before they can bring up the bill to send more class-action lawsuits to federal courts.

Last year’s version of the bill is likely to receive approval by the Senate when it comes to the floor next week or the week after. But it’s the debate in the interim — between sponsors of the bill and opponents, including a significant number of Democrats and their allies in the consumer rights and trial lawyer lobbies — that has the potential to delay, and possibly even scuttle, the measure.

Senate Minority Leader Harry Reid (D-Nev.) is backing Senate Judiciary ranking member Patrick Leahy’s (D-Vt.) desire to have the measure go through committee before coming to the floor. That may seem like a modest request, but supporters of the bill say that it has the potential to destroy the bipartisan compromise that a handful of Democrats forged with Republicans a year and a half ago.

“It’s a delicate compromise, and if you reopen this in any way, it could very well spin out of control,” warned one knowledgeable Senate Democratic aide. “There are more votes to move the bill to the right than to move it to the left.”

Indeed, Leahy strongly opposes the bill because he believes it would make it harder for consumers to seek damages from corporations they claim have wronged them. Leahy wants the bill to go through committee, because the current bipartisan compromise was never put before the panel for approval last year.

The stick that Democratic opponents of the bill are wielding is a series of amendments that, if offered in committee, could trigger conservatives on Judiciary to respond with proposals that make the bill less attractive to the Democratic moderates who currently support it, sources say. That, in turn, could rob the bill of the 60-plus supporters needed to beat back a filibuster.

Still, Reid spokesman Jim Manley said the Minority Leader “is a big believer in regular order. He likes to see bills go through committee.”

Considering that this Wednesday’s meeting of the Judiciary Committee will likely be dominated by a vote on President Bush’s nominee for attorney general, Alberto Gonzales, it is unlikely that Chairman Arlen Specter (R-Pa.) would bring the bill up for consideration. But a Specter aide said he has not ruled out the possibility.

However, neither Specter nor Senate Majority Leader Bill Frist (R-Tenn.) has decided whether to agree to Democratic requests to hold committee action first or to simply bring the measure straight to the floor.

If the bill comes to the Senate floor having sidestepped committee action, however, it may become more difficult for Frist to get Reid to agree to limit debate to germane amendments. Frist’s refusal last year to allow Democrats and Republicans to offer non-germane amendments caused even Democratic backers of the bill to block its consideration.

That’s why Democratic supporters hope that the more liberal wing of the Caucus will limit its opposition to the merits of the bill and not offer extraneous amendments, such as an increase in the minimum wage, which could put Democratic moderates in a sticky position.

Last year, Democrats, such as Sen. Edward Kennedy (Mass.), sought to add amendments that would increase the minimum wage and address other social issues unrelated to the bill. A Kennedy spokeswoman said he has not ruled out offering similar proposals on the floor this year.

It is unclear whether moderate Democrats who support the measure will stand with their more liberal colleagues and vote for the non-germane amendments.

Aides to moderate Democrats said their bosses have not yet decided how to handle votes on extraneous amendments, but that they generally support allowing Democrats to offer them.

“I think it’s safe to say that the [bipartisan] coalition will work to keep the bill clean from any changes that would alter the compromise,” said Bill Ghent, spokesman for Sen. Tom Carper (D-Del.), a backer of the bill. “But right now we’re not prepared to deal with hypotheticals.”

Even if floor debate is limited to germane amendments, opponents are lining up relevant amendments to offer.

Kennedy, for example, may offer a proposal to exempt wage-and-hour disputes and civil rights claims from being sent to federal courts if they are brought under state law.

Sandy Brantley, a lobbyist with the liberal group Alliance for Justice, said that workers who are denied overtime or those who have suffered discrimination are not the intended targets of the bill. Instead, the bill is aimed at curbing lawsuits in which lawyers file a claim of fraud for thousands of nameless, faceless clients in order to reap coupons of modest value for consumers and millions of dollars in lawyers’ fees for themselves.

“This would be adding layers of procedure and delay for workers who are only seeking their fair day’s pay,” said Brantley. “Consumer cases would still go to federal court.”

Brantley added that more than 30 states ban genetic discrimination, while the federal system does not. Sending genetic discrimination class-action cases to federal court, she argued, would only make it harder for plaintiffs to receive justice.

Additionally, Sen. Jeff Bingaman (D-N.M.) is likely to offer an amendment to prevent federal judges from dismissing class-action cases that involve several state laws.

Opponents of the bill accuse industry groups of hypocrisy, saying they’ve been simultaneously telling Congress that multistate class actions should be heard in federal court even as they argue in class actions that are already under way in federal court that multi-state laws make it impossible for the federal bench to adjudicate them.

Consumer activists argue that the federal courts are increasingly setting precedents to deny certification for classes in multistate cases, meaning that if the class-action bill does pass, many consumers may have no venue in which to sue corporations that they accuse of wronging them.

Lobbyists say that recent events may also help them shoot down another part of the bill, involving what is known as “mass actions.” For example, individuals suing Merck, the maker of the arthritis drug Vioxx, could have their lawsuits consolidated into a mass action by a state judge.

Under the most recent version of the class- action bill, mass actions would also be sent to federal court, where they would be more likely to be dismissed.

An amendment to strike mass actions from being affected by the bill is likely to come up in both committee and on the floor.