Ending months of stalls and internal struggles, the Senate is poised today to approve a major package tightening ethics rules and overhauling lobbying laws.

After the bill swept through the House earlier this week, it faced a flicker of trouble from conservative Senators trying to rally opposition over earmark transparency rules they viewed as too weak.

But GOP Sens. Jim DeMint (S.C.) and Tom Coburn (Okla.) — leaders of the conservative charge — saw their hopes for blocking the measure wither on Wednesday as most of their Republican colleagues indicated they would swallow any reservations to get behind the reforms.

“Unfortunate as it is, this bill will be passed,” Coburn said. He said while many Republican Senators have reservations about the bill, “they have reproductive organs the size of BB’s that won’t let them stand up and do the right thing for our country.”

Because the package includes changes to Senate rules, backers must gather two-thirds of those voting to end debate, or up to 66 votes, since Sen. Tim Johnson (D-S.D.) is still recovering his health. Final approval requires a simple majority.

Most lawmakers will hold their noses to support the package. While some Republicans agree with DeMint and Coburn that the earmark language falls short, others lodged complaints that other reforms go too far. “It’s poorly put together, and puts Members and staff in a vulnerable position that will become a tool for campaign tactics,” said Sen. Richard Burr (R-N.C.).

Burr said he likely would vote against the bill on final passage but would support cloture — the more crucial of the votes.

Other Republicans said they would support the bill despite problems with it. Sen. Mel Martinez (R-Fla.) said he is worried a provision imposing a one-year, chamber-wide lobbying prohibition on top Senate aides who take downtown jobs will make it hard to attract talented staff. Nevertheless, he said, “It’d be hard to vote against a lot of good things because there are some bad things in there. We vote for imperfect legislation every day.”

The measure has no outright fans in the GOP Conference, aides said. But they will fall in line rather than risk publicly blocking an ethics reform package. “The political reality is that if people step out to oppose this, it’ll be hung around their necks as an image problem,” one GOP Senate aide said.

Passage of the measure will mark a major victory for Congressional Democrats, who campaigned against what they termed a Republican culture of corruption and promised to enact sweeping reforms if elected.

Leaders quickly found their reform pledges were easier made than kept. House Democrats, on their first day in power in January, adopted a package of rules changes that promised more transparency, banned gifts from lobbyists and tightly restricted privately funded travel. The Senate followed suit that month with a measure that rolled up rules changes with legal reforms to restrict lobbyists.

But then momentum stalled. House Democrats struggled to match the Senate legislation when senior lawmakers objected to a requirement that lobbyists report political checks they arrange for candidates. They finally passed a bill in May.

Pre-conference talks snagged on the contribution bundling issue, and then, on an objection from DeMint, who wanted to force Senators to adopt earmark reform that he authored and had gotten included in the first Senate bill.

With DeMint refusing to back down, House and Senate Democratic leaders bypassed the typical conference process to hammer out a compromise measure behind closed doors.

The House passed it Tuesday, 411-8.

Budget watchdog groups including Taxpayers for Common Sense and Citizens Against Government Waste remain united in opposition. Other outside reform advocates — including Public Citizen, Democracy 21, and the Campaign Legal Center — are praising it as a dramatic leap forward.

“This is some very impressive work they’ve put together,” Public Citizen’s Craig Holman said. “I think we’re about to get some strong lobbying and ethics reform.”