With support for House Ways and Means Chairman Charlie Rangel (D-N.Y.) slipping and a jobs package coming under fire, the Congressional Black Caucus faces what may be its most important week in years.

Will caucus members rally behind Rangel? And will they get rolled on a $15 billion jobs tax credit package they have opposed because it omits billions in infrastructure and a youth summer jobs program they argue are needed to jump-start employment?

Rangel’s tenuous hold on his chairmanship continued to slip Tuesday, with CBC member Artur Davis (D-Ala.), who also serves on the tax-writing panel, calling on him to step aside, and Democratic aides starting to question whether he can survive a vote on stripping his chairmanship.

“As far as the whole [Democratic] Caucus goes, I think the dam broke today,” said one House Democratic aide. “I think you are getting to the point where the numbers just aren’t there on this resolution.”

Democrats are facing a fusillade of Republican attacks charging that by standing behind the embattled chairman, they are proving themselves hypocrites on their pledge to clean up corruption in Congress. But leaders are wary of moving too quickly to urge Rangel aside lest they inflame senior CBC members who revere the 79-year-old New Yorker, a co-founder of their group.

“We are going to be meeting to discuss the best way forward,” Assistant to the Speaker Chris Van Hollen (D-Md.) said Tuesday evening.

Rep. Gregory Meeks (D-N.Y.), a senior member of the group, on Tuesday warned that “leadership and other Democrats and [the Democratic Congressional Campaign Committee] need to wake up and get their heads out of the sand.” Rangel, he said, is the victim of a smear campaign by conservative activists, and the party needs to rally behind him.

“We can’t react to it for fear of elections. Whether you win, lose or draw, you’ve got to stand up for what’s right,” Meeks said.

But since his ethics committee admonishment late last week for accepting a pair of corporate-sponsored trips to the Caribbean, Rangel has seen a steady trickle of politically vulnerable Democrats call for him to give up his gavel, with 10 mostly freshman and sophomore Democrats on record at press time calling for his ouster. The latest to add their names to the list: Davis, and freshman Reps. Ann Kirkpatrick (D-Ariz.) and Debbie Halvorson (D-Ill.). And those numbers could pile up in a hurry when Republicans force the issue to a vote on a resolution set to hit the House floor as soon as Wednesday.

But the Davis announcement in particular should be worrisome for Rangel allies, since the Alabama Democrat is both the first Ways and Means member and the first black lawmaker to call for Rangel to step aside as chairman. “Rep. Rangel has had a long and distinguished career and I respect his leadership, but I believe Congress needs to do more to restore the public trust,” Davis said. “An ethics committee admonishment is a serious event, and Rep. Rangel should do the right thing and step aside as chairman of the House Ways and Means Committee.”

The House Democratic aide called the development a dark omen for Rangel. “As you see more Members like Artur Davis come out, the rationale for supporting Rep. Rangel begins to disappear,” the aide said, adding that it would clearly be preferable for Rangel to step down. If Rangel wants to hold on to the post, the aide said, he needs to address his fellow Members “very, very soon.”

“Every minute that goes by and he has not done something to address this is a minute he loses and makes opposing the resolution harder.”

Davis first gained his seat on the panel as a replacement for then-Rep. William Jefferson (D-La.), a fellow CBC member. Then-Minority Leader Nancy Pelosi (D-Calif.) muscled Jefferson off the committee in 2006 after he was targeted in a bribery probe. Pelosi infuriated many CBC members with her handling of the matter, and the specter of that episode has lingered over the Rangel scandal. But not all CBC members joined the chorus of criticism at the time, including, very notably, Rangel.

How aggressively the CBC sticks up for Rangel now could determine whether he keeps his grip on his gavel. “It’s the $100,000 question right now,” one top Democratic strategist said. But as the ethics committee prepares to render its judgment in a wider probe of Rangel’s personal finances and fundraising activity, he may find his political backstop with the CBC is short-lived, this source said. “If any of those things come back negatively, it’s going to be extremely difficult to say there’s no penalty. They’re all politicians, and they understand that.”

The CBC’s position on the $15 billion Senate jobs tax credit package, meanwhile, is simple — members don’t want to back a business tax breaks that they don’t believe will create jobs when the programs they support, including a summer youth jobs program, face an uncertain future in the Senate.

House leaders are sympathetic to the CBC’s concerns but are eager to start putting points on the board and hope that the CBC will agree to promises that their concerns will be addressed in future bills instead. A House Democratic leadership aide noted, as has Pelosi, that there will be future jobs bills coming down the pike.

“This bill is a part of our jobs agenda,” the aide said, and there is only so much that can be included in this bill. “Reality is reality.”