But the talk radio star may have finally forced the party to seriously ponder cutting ties after he branded a third-year law student at Georgetown University a "slut" and a "prostitute" for her congressional testimony about U.S. President Barack Obama's contraception policies.
"While Republican leaders owe no apology for Mr. Limbaugh's comments, they do have a responsibility to repudiate them — and him," the Washington Post wrote in a weekend editorial.
"For the good of U.S. political culture — or at least its own political self-interest — the GOP must distance itself from Mr. Limbaugh."
Conservative David Frum, the Canadian-born pundit and former George W. Bush speechwriter, has warned Republicans for years about the dangers Limbaugh poses to the party.
On Sunday, he described Limbaugh's weekend apology to Fluke, coming in the face of fleeing advertisers and suggestions she has grounds for a libel lawsuit, as "about the most graceless apology ever."
"What is good for Rush Limbaugh is not necessarily what's good for the Republican party," Frum added on CNN's "Reliable Sources."
While Limbaugh may be taking a hit, Frum said, "he leaves the party behind him in a smoking ruin."
A seventh advertiser jumped ship on Sunday, pulling its ads from "The Rush Limbaugh Show," the highest-rated radio show in the U.S. airing three hours a day, five days a week on 600 radio stations across the country.
ProFlowers said on its Facebook page that Limbaugh's comments "went beyond political discourse to a personal attack and do not reflect our values as a company."
On his show last Wednesday, Limbaugh said Fluke's testimony that birth control should be covered by health insurers, in part to help women deal with painful health conditions, "makes her a slut, right?"
"It makes her a prostitute. She wants to be paid to have sex. She's having so much sex she can't afford the contraception. She wants you and me and the taxpayers to pay her to have sex."
He added that if taxpayers were to be saddled with such bills — itself a misstatement since no tax dollars would pay for the benefits, only employers and health insurance companies — then Fluke and other "feminazis" should provide some kind of payback.
"We want you to post the videos online so we can all watch," said Limbaugh.
Amid the uproar, Obama personally called Fluke, 30, on Friday to console her. He was promptly mocked by Limbaugh for doing so, a day before the radio host issued his public apology.
Meantime, Republicans — both on the campaign trail and on Capitol Hill — issued tepid condemnations of Limbaugh's remarks, suggesting a reluctance to take him on.
Indeed, conservative columnist George Will said Sunday that Republican leaders are scared of Limbaugh, including John Boehner, speaker of the House of Representatives.
"Boehner comes out and says Rush's language was inappropriate. Using the salad fork for your entrée, that's inappropriate. Not this stuff," Will said on ABC's "This Week."
"And it was depressing because what it indicates is that the Republican leaders are afraid of Rush Limbaugh. They want to bomb Iran, but they're afraid of Rush Limbaugh."
Limbaugh, a one-time painkiller addict who's been married and divorced three times, earns US$400 million a year. He's attended Republican confabs on party strategy in recent years, and was the keynote speaker at the 2009 Conservative Political Action Conference, where he brought the crowd to its feet when he urged them to take back their country.
Presidential hopeful Newt Gingrich disputed the notion that Limbaugh wields serious influence over the party, calling it a "silly" suggestion.
"The Republican party has four people running for president, none of whom are Rush Limbaugh," he said Sunday.
But other conservatives have expressed dismay over the damage Limbaugh has likely caused the party.
"We had 2 young women at a dinner party tonight. Both Republican-oriented. Both lost to GOP by events of past week. Thanks Rush," Frum tweeted on Saturday night.
Frum, indeed, warned three years ago that Republicans "would regret conceding so much power to Rush Limbaugh." The piece in New York magazine later caused him to be blacklisted from Fox News, Frum has said.
Carly Fiorina, the vice-chairman of the Republican party's Senate Campaign Committee, called Limbaugh's remarks "insulting, incendiary and a distraction."
Sen. Scott Brown, a Massachusetts Republican and the father of two girls, also called on Limbaugh to apologize, calling the remarks offensive and reprehensible.
But Limbaugh's apology for his "insulting word choices" has done little to douse the flames of outrage, thanks in part for his reiteration of what drives his opposition to health insurers providing birth control coverage.
"I think it is absolutely absurd that during these very serious political times, we are discussing personal sexual recreational activities before members of Congress," wrote Limbaugh.
"I personally do not agree that American citizens should pay for these social activities. What happened to personal responsibility and accountability? Where do we draw the line? If this is accepted as the norm, what will follow? Will we be debating if taxpayers should pay for new sneakers for all students that are interested in running to keep fit?"
Hours after the apology, a sixth advertiser — Carbonite, an online data backup company — pulled its ads from Limbaugh's show.
"No one with daughters the age of Sandra Fluke, and I have two, could possibly abide the insult and abuse heaped upon this courageous and well-intentioned young lady," CEO David Friend said in a statement.
"Mr. Limbaugh, with his highly personal attacks on Miss Fluke, overstepped any reasonable bounds of decency. Even though Mr. Limbaugh has now issued an apology, we have nonetheless decided to withdraw our advertising from his show."
It's hardly the first time Limbaugh's been in hot water. Last year, the rotund radio star caused an uproar by mocking first lady Michelle Obama's efforts to combat childhood obesity, suggesting she was fat and failing to follow her own dietary advice.
He also once mocked Michael J. Fox, the Canadian-born actor who suffers from Parkinson's disease.
But his vitriolic foray into an already bizarre debate in the United States about contraception — occurring about 50 years after the birth control pill was introduced to American women — isn't expected to do any favours for the party among female voters, regardless of Republican insistence that their battle is about religious freedom, not contraception.
Female voters made up almost 54 per cent of the electorate in the 2008 presidential election, and are expected to out-number men in November as well.
And a recent poll by CBS News and the New York Times found that 72 per cent of women support requiring private insurance companies to provide contraceptive coverage at no cost to beneficiaries.
Understandably, the Obama re-election team seems in no hurry to let the controversy drop.
"What Rush Limbaugh said about that young woman was not only vile and degrading to her, but to women across the country," David Axelrod, a senior campaign adviser to Obama, told ABC on Sunday.