House Democratic leaders are forging ahead with a campaign finance reform package they were forced to pull last Friday, confident they now have the support they need to muster a majority when it hits the floor today.

The measure, called the DISCLOSE Act, comes in response to a hot-button Supreme Court decision in January that lifted limits on political spending by outside groups. And top Democrats have been making the case to their rank and file that the bill, which would impose new requirements that groups sponsoring ads and other political communications identify themselves and their top donors, is a must-pass to keep hostile corporate money from flooding into the midterms.

Leaders scotched a planned vote on the bill last week after members of the Blue Dog Coalition and the Congressional Black Caucus raised concerns.

At the time, senior Democratic sources said that while they were taking the Blue Dog gripes seriously, it was the objections of the CBC that dragged down the whip count and forced leaders to punt.

Heading into the floor vote, the CBC still appears to hold the key to passage. And several members of the group were tight-lipped about how they plan to vote after their weekly huddle on Wednesday. “We’re still in the process of talking about it. We’re still discussing it,” CBC Chairwoman Barbara Lee (D-Calif.) said.

At least one CBC member on Wednesday made plain her intentions — to vote against the package. Rep. Donna Edwards (D-Md.), a veteran campaign finance reformer, had been in talks with leadership about her proposal to widen a carve-out that top Democrats had negotiated to exempt the National Rifle Association. Rep. Chris Van Hollen (D-Md.), the bill’s author, was frank in his appearance before the House Rules Committee on Wednesday in describing the deal as necessary for gathering support from Democratic holdouts. But CBC members have howled since its rollout last week, pointing in part to the political challenge of defending an exemption tailored for the gun lobby in districts plagued by gun violence.

Edwards, in a floor speech Wednesday, called the tweak “deeply troubling, both on the politics and the policy. … Shame on us.”

The CBC is also pushing back over the inability of the Senate to pass a jobs package that includes funding for summer jobs programs, a protest that could be hardening the group’s opposition to another priority of party leadership.

And Democratic vote-wranglers were still working Wednesday to convince a handful of recalcitrant liberals upset by the NRA deal.

“They’re working the floor very hard, because they’re still short,” said Rep. Raúl Grijalva, a co-chairman of the Congressional Progressive Caucus. The Arizona Democrat paraphrased the pitch from Speaker Nancy Pelosi (D-Calif.): “This is not perfect. We needed to carve it out in order to get the Blue Dogs. Otherwise we can’t pass it. If we don’t pass it, the consequences are dire for the party.”

In the Senate, while Majority Leader Harry Reid (D-Nev.) may have promised to bring it to the floor, the fate of the DISCLOSE Act appears dim at best.

Although Democrats are trying to identify a handful of Republicans to break ranks with their leadership and support the measure, GOP lawmakers said they are standing firm at this point. For instance, National Republican Senatorial Committee Chairman John Cornyn (Texas) said Wednesday that Republicans are “largely united [against] … this exercise in hypocrisy.”

Similarly, Sen. John McCain (Ariz.), who has been a prime Republican sponsor of campaign finance measures in the past, also said he opposes the bill. “I’m very disturbed. It basically gives free rein to the unions,” McCain said.

But while the House and outside organizations have largely been focused on finding Senate Republicans to vote for the bill, they’ll need to shore up Democratic support before any Republicans consider jumping on board.

Sen. Frank Lautenberg has been one of the bill’s most outspoken Democratic critics, and the New Jersey Democrat said Wednesday that he remains strenuously opposed to the bill’s carve-out for the NRA.

“I think that exempting them from requiring the transparency that everyone is subjected to sends a bad signal. … It’s just an unacceptable condition when you consider all the attention that’s being paid to transparency,” Lautenberg said, pointing to public support for an end to secret holds and other backroom deals.

“It may be good for a state or two, but for our national good it doesn’t square,” Lautenberg said, adding that he is hoping to build enough opposition to block the legislation if the carve-out remains.

“We hope we can muster enough opposition to keep it from happening,” he said.