Rep. Charlie Rangel’s (D-N.Y.) decision to step down as the Ways and Means Committee chairman on Wednesday had as much to do with 2010 election politics as it did with House rules, disclosure requirements and his recent admonishment by the ethics panel.

It was vulnerable House Democrats, particularly first- and second-term Members high on the GOP’s 2010 target list, who were the first to publicly distance themselves from the 20-term incumbent. The constant drip created the groundswell that finally convinced Democratic leaders that they did not have the votes to keep Rangel in his post and, moreover, that forcing such a vote could be a political disaster.

Many of the freshman and sophomore Democrats “made it known that the votes weren’t going to be there,” said one aide to a first-term Democrat who faces a competitive race this fall. The aide added that there was no coordinated effort on behalf of the freshman class but that “over the course of the beginning of this week,” the Caucus’ junior members “were making their intentions and positions known.”

“Everybody walked the plank before, but it was tough to see how that was going to happen this time,” agreed another aide to a vulnerable Democratic freshman.

Having been elected on a platform of good government and by riding a wave of anti-incumbent fervor the past two election cycles, these Democrats are particularly mindful of the consequences of not living up to their promises.

Underscoring the potential political peril that ethics controversies carry, Republicans were quick to seize on Rangel’s extensive political giving. A Roll Call analysis found he’s doled out or helped raise about $5 million for Democratic candidates and parties since 2005 — and the National Republican Congressional Committee singled out the long list of candidates who have not purged the donations from their bank accounts.

The number of Democrats who are returning past Rangel contributions or contributing the money to charity is growing by the day. Nearly all who have done so were elected in 2006 or 2008 and are in races that are competitive.

“What we’d said all along was we’d let the investigation follow to an end” and then purge the money if Rangel was found to have committed wrongdoing, said a staffer for a freshman Democrat who quickly donated the contributions from Rangel to charity. “We had always felt we were prepared for this thing.”

“Once the first couple of us started making the decision early, it made some space for people to follow quickly behind,” the staffer continued. “Instead of having declining support over the next three or four days, [the Democratic leadership] just sort of pulled the plug.”

One freshman, Rep. Mark Schauer (D-Mich.), even used his decision to donate $14,000 in Rangel contributions to charity in a fundraising pitch of his own.

“As a matter of conscience, I formally called on Congressman Charles Rangel to step down as Chair of the House Ways and Means Committee, following a report that he knowingly violated House ethics rules,” Schauer wrote in the e-mail to supporters, noting that he was giving away the contributions in keeping with that principle. “I’m committed to fixing what’s broken with Washington — even if that means standing up to my own party’s leadership — but I can’t do it alone.”

A small number of vulnerable Democrats have benefited from not taking any Rangel contributions. New York Reps. Scott Murphy and Bill Owens, both elected in special elections in 2009, did not have donations on their books, though the NRCC still whacked Murphy for not calling for Rangel to step down as chairman. And first-term Rep. John Adler (D-N.J.) returned donations that he had received from Rangel in 2008 and has not taken any contributions since then.

There are plenty of junior Members still holding on to their Rangel contributions, despite facing competitive races in November and taking a bashing from Republicans.

New York’s vulnerable Democrats are in an especially precarious position, given the friendship and support that Rangel has offered many in the delegation over the years. Sophomore Rep. Dan Maffei and freshman Reps. Eric Massa and Michael McMahon are among the top recipients of Rangel’s fundraising help if one includes funds raised in tandem via the Rangel Victory Fund. None have returned the money, though all three issued statements Wednesday lauding Rangel’s decision to step down.

Republican political consultant Jason Roe predicted that it was just a “matter of time” before the rest of the vulnerable Democrats ended up “giving that money back or dispensing of it somehow.”

“If they have any sense they are going to figure out how to deal with it now,” Roe said. But he added, “I hope they are stupid enough to drag this out.”

Roe, who is advising one of Schauer’s GOP opponents, Brian Rooney, said that even those Democrats who have purged the Rangel funds are not in the clear. “It was transparently obvious that Charlie Rangel had ethical issues, and these politicians waited until there was some official action to warrant taking action on their own,” he said. “This was not something that was done of their own desire. This was something they were politically forced to do.”

A Democratic strategist agreed that vulnerable Democrats who have received contributions from Rangel over the years ought to “write a check to the Red Cross or something.”

“That’s probably a wise thing to do,” the strategist said, adding that Rangel is “going to understand the deal. … I don’t think he’s having his feelings hurt.”

The strategist also said he did not think the Rangel story was going to be the main thing weighing Democrats down going into the November elections.

“This election, barring something huge happening, is about jobs,” the consultant said.

However, he conceded that Rangel’s situation is “not helpful,” particularly given the fact that there are further matters involving Rangel pending before the ethics panel. “No one thinks they’re going to get resolved extremely well,” he said, expressing a sentiment shared by the Democratic staffers Roll Call spoke to.

In particular, the staffers lamented the drip-drip-drip nature of the ethics revelations, which have dragged out for more than a year.

“It would have been nice to have everything come out at once, just to get it over with,” said one of the aides to a freshman Democrat.

And at least one aide expressed confidence that the issue would die down now that Rangel has stepped down from his chairmanship. “If we had voted to let him stay, and if the vote had failed, I think it would have been an issue, but now I really don’t think it’s going to resonate,” the aide said.