How’s this for political cowardice? Right-wing bloviator Rush Limbaugh launches a vile attack, full of sexual insults and smarmy innuendo, against a young woman whose only offense was to speak her mind. Asked to comment, the leading Republican presidential candidates — who bray constantly about “courage” and “leadership” — run from the bully and hide.

“I’ll just say this, which is, it’s not the language I would have used,” said Mitt Romney. I wonder what language Romney thinks Limbaugh should have used to call Georgetown University law student Sandra Fluke a “slut” and a “prostitute.”

“He’s being absurd, but that’s, you know, an entertainer can be absurd,” said Rick Santorum. I doubt seriously that Fluke found it entertaining, in an absurdist kind of way, when Limbaugh creepily suggested she and other women post sex videos on the Internet. I hope and trust that Santorum wasn’t entertained, either.

As for Newt Gingrich, the cat got his tongue, and apparently didn’t return it until Limbaugh had already apologized to Fluke for his “insulting word choices.” Gingrich went out on a limb Sunday and called Limbaugh’s apology “appropriate.”

Which it wasn’t, by the way. Limbaugh’s claim that “I did not mean a personal attack on Ms. Fluke” is an obvious lie; there’s no impersonal way to call a woman a slut. His abuse of Fluke — who advocated publicly last week that the health insurance she receives through Georgetown, a Catholic university, should be required to cover birth control — was no one-time gaffe. He poured it on, day after day.

And when he decided to back down, Limbaugh apologized only for his choice of words — not for the bitter misogyny he now believes he should have cloaked in prettier language.

Of the GOP candidates, only Ron Paul seemed to notice the insincerity of Limbaugh’s regret. “I don’t think he’s very apologetic,” Paul said. “He’s doing it because some people were taking their advertisements off his program. It was his bottom line he’s concerned about.”

Why will Paul say the obvious while Romney, Santorum and Gingrich are barely willing to clear their throats? Because Paul, who is in this campaign to spread the gospels of libertarianism and Austrian economics, knows he can’t win the Republican nomination. The others, who think they do have a chance to win, are afraid of making Limbaugh into an enemy — or, in Romney’s case, into more of an enemy than he already is.

So let’s get this straight: These guys want us to believe they’re ready to face down Vladimir Putin, Mahmoud Ahmadinejad, Kim Jong Eun, the Taliban and what’s left of al-Qaeda. Yet they’re so scared of a talk-radio buffoon that they ignore or excuse an eruption of venom that some of Limbaugh’s advertisers — nine, at last count, have said they would no longer sponsor the show — find inexcusable.

I would have thought that crass political calculation might lead the would-be GOP nominees to the correct position on Limbaugh’s rhetorical depravity. Women constitute a majority of voters. If they merely lean toward the Democrats this fall, as they usually do, Republicans still have a mathematical chance to win the presidency by racking up a big majority among men. But if the GOP is perceived to endorse Limbaugh’s hateful rhetoric about “feminazis” and his stance of male grievance, female voters could turn what looked like a winnable election for Republicans into a debacle.

But Romney, Santorum and Gingrich are so frightened of being labeled insufficiently conservative — in this context, meaning “not nice enough to Rush” — that when given the opportunity to show some backbone, they go all wobbly.

What does this say about these men? To me, it suggests that maybe Romney isn’t as smart and disciplined as he’s said to be. Maybe Santorum isn’t as sincere, compassionate or moralistic as he appears. Maybe Gingrich’s vaunted intellectual courage is afraid of its own shadow.

As it happens, President Obama called Fluke last week to express his support. Perhaps, as a father, he imagined how he would feel if one of his daughters were attacked so viciously. Perhaps, as a canny politician, he saw the benefit of denouncing Limbaugh’s caustic caterwauling.

Either way, Republicans spent yet another week talking about contraception. Casey Stengel once said that “most ballgames are lost, not won.” He could have been talking about elections.

eugenerobinson@washpost.com