Beginning on Jan. 15, Bernie Sanders has been the victim of a Jeremy Corbyn-style mugging. Elizabeth Warren started it by teaming up with the ghouls at CNN to accuse him of saying that a woman could never win the presidency. Joe Biden followed up by charging his staff with doctoring a video to make it look like he favors cutting Social Security. Finally, Hillary Clinton joined in the pile-up by calling him ineffectual, duplicitous, and a misogynist to boot.

It was all too predictable. The higher Sanders climbed in the polls, the sooner the Democratic establishment would launch an offensive aimed at stopping him from winning the nomination.

But Sander response was predictable as well – predictably weak, that is. Instead of letting Warren have it for a story that she obviously concocted out of thin air – Sanders’s anti-sexism credentials are impeccable – he held his tongue in the hope that the controversy would fade away. Instead of blasting CNN for its outrageously biased questioning during the Iowa debate, he let that go as well.

As for the “doctored” video, he could have pointed out that Biden was lying since the clip was clearly not tampered with at all. But he didn’t. Then, however, he made matters worse by apologizing for an article by a supporter named Zephyr Teachout pointing out that credit-card companies located in Biden’s home state of Delaware “bankrolled” his political career and that he paid them back “by spearheading a bankruptcy bill that made it harder for Americans to reduce their debts and helped cause the financial crisis.”

The piece, entitled “‘Middle Class’ Joe Biden has a corruption problem,” also noted that a healthcare-industry super-PAC is now financing his presidential bid and that what he’s given the industry in return is a “healthcare proposal that preserves the power of the insurance industry and leaves 10 million Americans uninsured.” As for climate change, Teachout observes that Biden signed a pledge not to take fossil-fuel money and then broke it and that the climate policy he’s come up with since “has gotten dismal reviews from several leading environmental group.”

What about this was wrong? The answer is nothing. Yet Sanders told CBS News: “It is absolutely not my view that Joe Biden is corrupt in any way. And I’m sorry that that op-ed appeared.”

It’s not that Teachout was incorrect, in other words, merely that her facts were inconvenient. Yet what made it doubly ironic is that Teachout left out the most important incident at all: the $50,000-a-month post that Biden allowed his son Hunter to take with one of the Ukraine’s most notorious oligarchs at a time when the then-vice president was supposedly overseeing the Ukrainian anti-corruption effort.

It’s as if Eliot Ness had allowed his kid to go to work for Al Capone. If Teachout forgot to bring it up, it’s presumably because she knows that Trump will use it to clobber Biden if he makes it to the general election and that, good Democrat that she is, she doesn’t want to give him anything by way of encouragement. But it doesn’t undo the fact Biden was guilty of such a massive conflict of interest that even the New York Times was taken aback or that Trump will use it not only against Biden, but against Democrats in general for covering up their candidate’s obvious corruption.

It won’t be pretty. As for Clinton, her comments were so over the top that Sanders should have come out with both guns blazing. She told the Hollywood Reporter that she stood by her comments in an upcoming documentary that “[n]obody likes him, nobody wants to work with him, he got nothing done. He was a career politician. It’s all just baloney and I feel so bad that people got sucked into it.”

She then twisted the knife by refusing to say if she would support Sanders if he gets the nomination: “I will say, however, that it’s not only him, it’s the culture around him. It’s his leadership team. It’s his prominent supporters. It’s his online Bernie Bros and their relentless attacks on lots of his competitors, particularly the women. And I really hope people are paying attention to that because it should be worrisome that he has permitted this culture – not only permitted, [he] seems to really be very much supporting it.”

So she thinks Sanders is a sexist too. There are a lot of things Sanders could have said in response. He could have pointed that the Clinton Foundation has raked in $10 million or more from Saudi Arabia, a country that keeps women in something close to slavery, and that, as secretary of state, she backed a Saudi-financed jihad aimed at enslaving women in Syria as well. But all he could muster was a weak joke: “On a good day, my wife likes me, so let’s clear the air on that one.”

It’s all too reminiscent of Corbyn, the now-disgraced leader of Britain’s Labor Party, who failed to fight back against cooked-up charges of anti-Semitism and instead responded with one timid apology after another. It did nothing to appease his rightwing attackers and only left his followers feeling demoralized and confused. If Sanders continues on the same path, the results will be similar. He’ll look frightened and indecisive, his followers will lose heart, and he’ll end up in a dispiriting second or third place in Iowa and New Hampshire.

If so, a few of us more skeptical sorts will reply that by running as a socialist for the Democratic nomination, Sanders was attempting to straddle two very different worlds and, as a result, ended up tumbling in between. Instead of fighting the Democrats, he set out to make nice and has gotten in the back in return.