DETROIT — Democrats turned their presidential debate into a spiral of attacks against one another here Wednesday night, spending more than two hours squabbling over policy details and questioning each other’s honesty or character but only sporadically making a strong case for defeating President Trump in 2020.

In one way, the debate was exactly what had been expected, a series of attacks against former vice president Joe Biden, the leader in the polls who had faltered in the first debate in Miami and needed to rebound in Detroit. He accomplished that, but barely so and perhaps by opening himself up to future criticisms.

In another way, the second night of debating was not at all what Democrats had expected or likely wanted. By the end of the evening, the candidates had done as much to make a case against one another as against the president, without offering much in the way of an aspirational message or connecting directly with the voters they will need to win the presidential election.

2020 Democratic presidential candidates worked the media in the spin room following the second Democratic debate in Detroit on July 31. (The Washington Post)

The reality is that little changed as a result of the debate. The absence of clear winners and the absence of the emergence of a candidate with a hopeful message for a broader audience produced a status quo ending.

Biden was not the only candidate who came under attack. Sen. Kamala D. Harris (D-Calif.), who clashed with Biden in Miami in June, found herself a target, and not just from Biden. Sen. Cory Booker (D-N.J.) attacked Biden on criminal justice issues and found his record as the mayor of Newark pilloried by the former vice president.

Tuesday’s debate highlighted the ideological fissures within the party, but the candidates generally remained on a higher plane of substantive disagreement. Wednesday’s debate included moments when those same issues — health care or immigration or climate change — were debated, but in ways that probably left viewers confused about whom to believe or what those differences were really about.

By the time it ended, almost no one had escaped the fallout. Biden did better than in Miami, but also emerged battered over his record in the past and his ideas for the future, both of which one or another rival found inadequate. Harris delivered a more uneven performance than in Miami. Booker, by his aggressiveness toward Biden, made his bid to move up in a race where he has struggled.

What took place showed the limitations of a field of more than 20 candidates and a set of qualifications for participation that encourage conflict and the pursuit of viral moments at the expense of more civil and substantive discussion about the problems facing the country.

Biden began the night with an off-mic quip. As Harris walked onstage and greeted him, he joked, “Go easy on me, kid.” But it was Biden who hit first, attacking Harris for her new health-care proposal that would move the country toward Medicare-for-all, but only after a 10-year transition period. Biden found fault with the plan and with Harris’s explanation of it, calling it at one point “double talk” that would never be successful against the incumbent president.

“You’re just simply inaccurate,” Harris responded, and the two set off on a set of exchanges, interrupted occasionally by others, that was both flat in tone and not particularly illuminating to a television audience not familiar with the complexities of what she was offering.

Biden was accused of not being bold enough and in turn attacked his attackers for not being honest with people about the true cost of Medicare-for-all or the size of the tax increase needed to pay for it. He said his plan would not eliminate private insurance but would not require anyone to keep it if they preferred a government plan. He called the criticisms “a bunch of malarkey.”

Booker, having signaled his readiness to confront Biden on criminal justice issues, was good to his word. But the first volley came not over that issue but immigration. Biden was pressed by New York Mayor Bill de Blasio to say whether he had pushed President Barack Obama to change the administration’s deportation policies.

Biden deflected the question, praising Obama’s immigration policies and calling it “bizarre” to in any way compare those policies with the Trump administration. When de Blasio pressed him again, he declined to answer.

“I was vice president,” he said. “I am not the president. I keep my recommendation to him in private. Unlike you, I can expect you would go ahead and say whatever was said privately with him. That is not what I do.”

Booker pounced. “Mr. Vice President, you can’t have it both ways,” he said. “You invoke President Obama more than anybody in this campaign. You can’t do it when it’s convenient and then dodge it when it’s not.”

When the discussion turned to criminal justice, Booker attacked Biden for sponsoring crime legislation in the past that had resulted in massive incarcerations, particularly of black men. “This is one of those instances where the house was set on fire and you claimed responsibility for those laws,” he said. “And you can’t just now come out with a plan to put out that fire.”

Biden then attacked Booker for policing problems in Newark when he was the mayor, saying Booker had instituted a stop-and-frisk policy that drew sharp criticism and that he had done little to clean up the problems.

“Mr. Vice President, there’s a saying in my community,” Booker responded, standing next to Biden. “You’re dipping into the Kool-Aid and you don’t even know the flavor. You need to come to the city of Newark and see the reforms that we put in place.”

And so it went. Gov. Jay Inslee (D-Wash.) found Biden’s climate plan lacking urgency. Biden strongly disagreed. Former housing secretary Julián Castro came under fire from Biden for seeking to decriminalize the southern border. “If you cross the border illegally, you should be able to be sent back. It’s a crime,” Biden said.

“Mr. Vice President, it looks like one of us has learned the lessons of the past and one of us hasn’t,” Castro said.

Sen. Michael F. Bennet (D-Colo.), lamented that the Democrats were wasting time litigating the past and ignoring both the urgent problems of today and the threats posed by the Trump administration. His voice went largely unheard by the others on the stage.

By the conclusion Wednesday, it seemed almost as if the Democrats had decided to put their worst face forward. Their disagreements overwhelmed almost everything else. Attacks on Trump were infrequent. And the absence of a message of hope or uplift seemed a big missed opportunity.

The two nights of debating in Detroit neither moved toward resolving the substantive differences nor helped answer which Democrat is best prepared to run against Trump in 2020. More Democrats currently see Biden that way, but the campaign will bring more challenges to him.

Those in the progressive wing of the party left Detroit emboldened by what happened on Tuesday night, when Sen. Elizabeth Warren (Mass.) and Sen. Bernie Sanders (I-Vt.) fended off attacks from more moderate rivals. Other Democrats privately sounded more worried that the two sessions provided Republicans with ample ammunition for a general election.

What Detroit showed most of all is that the Democrats face a lengthy period in which they will be asked to sort out basic questions of who they are and how they plan to run against an unconventional president who has changed many of the rules of politics and already is in general-election mode.