Best not to ask GOP fundraising legend Georgette Mosbacher about the state of her beloved party unless you want an earful. The co-chair of the RNC’s Finance Committee (and CEO of Borghese cosmetics), Mosbacher is “mad as hell” about the myriad ways the “brand has been tarnished”: the sorry state of the presidential primary process, the ongoing alienation of Latino voters, the “outrageous” Senate candidates that the party ran this cycle, the epic failure of the fiscal-cliff negotiations, and, most recently, the House’s dithering over disaster aid for the victims of superstorm Sandy.

“I’m angry!” fumes Mosbacher. “I’m angry about the stupid mistakes that were self-inflicted.” It’s this last part she finds the most enraging. Though she believes the party has “unfairly” been defined by its recent mistakes, she is very clear about where the ultimate blame lies: “We did it to ourselves.”

Mosbacher is, of course, not alone in her ire. Postelection, you can’t swing a dead cat without hitting a hastily assembled group of Republican leaders laboring to figure out where the party went wrong last cycle and how to get it back on track. So far, however, Mosbacher is unimpressed by their efforts.

“I have not seen an honest postmortem assessment yet,” she told me. “I have not seen anything that gives me any comfort right now.”

This is an unfortunate development for the GOP, because, as Mosbacher explained it to me this weekend: “I’m not writing any checks, and I’m not asking anyone else to write any checks until I hear something that makes sense to me.”

The root problem, as she sees it: the sorry state of the party’s leadership in Washington.

Take the implosion of certain Senate candidates, she says. “One or two bad apples—excuse the cliché—really can spoil the whole thing. But it’s incumbent on our leadership to know who those are. Don’t tell me these people didn’t know who they were before they spewed their nonsense.” Mosbacher grows increasingly agitated. “How did they get this far? Where was the leadership to stop that?”

OK. So the party’s finance co-chair is disgusted to the point where she’s threatening to shut off the money spigot. That’s the bad news. Now for the worse news: she is not alone.

As Mosbacher tells it, many of her fellow mega-donors are vowing to sit on their wallets until something changes. “Since the election, there have been a lot of gatherings, a lot of meetings among those who are active in raising money,” she says. “There’s been one every week. There are a lot of us who are saying, ‘Just wait a minute.’”

Mosbacher adds, “The question is, ‘Are we united in drying that up?’ From the people I’ve talked to, the answer is, ‘Yeah.’”

Earlier this month, New York Republican Rep. Peter King caused a stir when, incensed by the House leadership’s refusal to vote on Sandy relief, he publicly called on area voters not to donate to his own party. “The Republicans have no problem finding New York when they’re out raising millions of dollars,” raged King. “I’m saying right now, anyone from New York or New Jersey who contributes one penny to congressional Republicans is out of their minds.”

King’s outburst—closely followed by a similar declaration of war by New Jersey Gov. Chris Christie—prompted a flurry of news reports about how much the GOP relies on New York funders. (State Republicans gave in the neighborhood of $378 million during the 2012 cycle, putting it No. 2 behind only California.) A scant hour after Christie’s denunciation, House leadership reversed course and scheduled an aid vote.

As far as Mosbacher is concerned, however, the damage was done. While “stupid,” the leadership’s fumble of the Sandy vote “was just that moment in time,” she says. “It only reinforced how angry we are about what they’re doing.”

If anything, says Mosbacher, the episode drove home the impact that New York—which she refers to variously as “the motherlode” and “the golden goose”—can have. “You know how loud we were. Let’s face it, it didn’t take long to turn that one around. It showed that the golden goose does have some pull.”

Now, she says, it’s time to tackle “the bigger issues,” subjects on which she and her fellow donors expect to be heard by party leaders before they hand out any more golden eggs.

“There’s one thing they understand,” she says with the confidence of a woman who has played at the highest level of the game for many years. “They understand money. Politics is about money. Make no mistake. They’re going to have to listen.”

And not merely listen. Mosbacher warns, “They may listen and not act. But that will be risky.”