Joe Biden was both the strongest – and weakest – candidate on stage

The life of a frontrunner isn’t easy. In a crowded field, you have to absorb all the incoming fire. When the other candidates on the debate stage finally run out of attacks, there are protesters in the audience who shout you down.

Such is Joe Biden’s suffering in this longest of presidential contests. Nine months into the race, and yet six months away from Super Tuesday, his frontrunner status has stagnated. It is not a happy place to find yourself: with a lead but no momentum.

Biden was both the strongest candidate on the debate stage on Wednesday, and the feeblest. He can sustain prolonged attacks and then sabotage his own sentences. If his central argument for the presidency is that the voters know what they’ll get, this much is true: they’ll get both the good and the bad Joe Biden.

On the single biggest dispute inside the Democratic party – whether to abolish private healthcare – Biden destroyed the happy talk of most of the candidates around him. He also destroyed the English language along the way.

So Biden correctly pinpointed the massive taxation imposed by Medicare for All as the fatal flaw in the plan adopted by all his major challengers.

When Sanders countered that Americans would save money because they would no longer pay premiums, Biden scoffed at the notion that employers would simply give that cash back to their workers.

“Well let me tell you something,” he said, “for a socialist, you’ve got a lot more confidence in corporate America than I do.”

It was a great line. But to arrive at his zinger, Biden confused every single detail of his own plan, as well as confusing the candidate standing next to him for Donald Trump, referring to Sanders as “the president’”.

It was like watching him place his briefing books inside a giant Vitamix: you could call the result a smoothie but it felt pretty lumpy.

“The option I’m proposing is Medicare for All – Medicare for choice,” he fumbled. “If you want Medicare, if you lose the job from your insurance – from your employer – you automatically can buy into this … And if you notice, nobody’s yet said how much it’s going to cost the taxpayer. I hear this large savings the president thinks – my friend from Vermont thinks – that the employer’s going to give you back if you negotiated as a union all these years, got a cut in wages because you got insurance.”

Supporting Joe Biden’s campaign depends on suspending your disbelief that anyone in public life for so long could speak so disjointedly.

Donald Trump’s earliest fans suggested that we should take him seriously, not literally. As it happens, Trump has graphically proved that we needed to take him seriously and literally. In Biden’s case, it’s maybe best if we skip over the literal stuff.

The Biden-Sanders slugfest was in many ways the most fascinating fight within the bigger donnybrook of the third Democratic debate. Watching two old heavyweights swinging at each other was a compelling sight, even if it left you wistful for their younger days.

As much as Biden cornered Sanders on the great healthcare debate, Sanders pummeled Biden on his weakest subject: the great Iraq debate.

Biden has embellished his story about supporting and opposing the war in Iraq to the point where truth and fiction cannot be reconciled. He speaks with less clarity than John Kerry explaining his contradictory votes for and against funding the war.

At Wednesday’s debate, Biden attempted to clean up his recent claims to having opposed the war. “I said something that was not meant the way I said it,” he explained, adding yet more confusion to the English language.

What he meant, apparently, was that he opposed the way the war was waged, “that in fact we were doing it the wrong way”. This was not so obvious when he told NPR that he opposed the war as soon as it started. Then again, he also told NPR in the same interview that “the details are irrelevant in terms of decision-making”.

It may be true that the debate over the Iraq war is irrelevant to most voters, not least after four years of Donald Trump’s laser-like focus on the details of what he’s watching on TV. But for Democratic voters in the primary states, Iraq cannot easily get brushed aside.

At this point, Sanders pounced in the way that only septuagenarian senators can. “The truth is, the big mistake, the yuge mistake, and one of the big differences between you and me, I never believed what Cheney and Bush said about Iraq,” Bernie declared, layering on the differences like so many slaps of Smuckers jam. “I voted against the war in Iraq and helped lead the opposition.”

As Bernie and Joe thrashed out their old disputes, there was a clear opening for the lesser-known challengers. Chief among them: Elizabeth Warren, the Massachusetts senator who may be the only candidate with a claim to having some sustained momentum in the polls.

Warren may be as radical as Sanders but she has the rare ability to build her arguments on what sounds like good-natured common sense instead of nitroglycerin.

Warren wants an immediate withdrawal of American troops from Afghanistan, with or without a peace deal with the Taliban – a position that would have been unthinkable for previous presidential candidates.

She explained the reason why in simple terms: because she can’t get a straight answer from the generals to one question. “Show me what winning looks like. Tell me what it looks like,” she said. “And what you hear is a lot of ‘uh,’ because no one can describe it. And the reason no one can describe it is because the problems in Afghanistan are not problems that can be solved by the military.”

They say that presidential campaigns are an x-ray into the candidate’s soul. That’s assuming the candidates still have souls, and that you need some expertise to see their true nature.

But you don’t need an x-ray to look into the souls of the Democratic candidates any more. They stand on the debate stage metaphorically naked.

Kamala Harris wants to talk about, if not directly to, Donald Trump.

Pete Buttigieg may be the only human being on the planet – and certainly the only one in South Bend, Indiana – who can talk in complete sentences and paragraphs.

Cory Booker wants to talk about when he was mayor of Newark and could get stuff done.

Julián Castro wants to goad old Joe Biden.

Beto O’Rourke wants to revive his former rockstar profile by talking mostly and emphatically about gun control.

Amy Klobuchar wants something reasonably centrist that reasonable people want.

And Andrew Yang wants to give away money like Willy Wonka, to a few lucky supporters, in the most Trump-like move that Trump never thought of.

They are a great chorus to the bigger drama that is Joe Biden’s decline and fall. Or Rocky-like rebound against the odds, when everyone said he was past his prime.

It was Joe Biden who memorably lampooned the doomed Giuliani campaign in 2008 by saying that the former New York mayor needed only three things to make a sentence: a noun, a verb and 9/11.

A decade later, Biden needs three things to make a sentence: a folksy anecdote, Barack Obama, and the kind of syntax that makes you wonder what on earth he’s thinking.

• Richard Wolffe is a columnist for the Guardian US. He is the author of Renegade: The Making of a President