MANCHESTER, N.H. — For months, he played the big-talking front-runner, swaggering if rarely steady, hoping voters would not linger long on the tautology of his premise: Joe Biden was the candidate who should win, he told fellow Democrats, because he was the candidate who could win.
So it was with some apparent humility — and then plenty of residual swagger — that Mr. Biden, days off a fourth-place debacle in Iowa, opened Friday night’s debate with an unusual prediction: He would probably do some more losing next week.
“I took a hit in Iowa,” the former vice president allowed. “I’ll probably take a hit here.”
Since joining the race last year, Mr. Biden has presented himself as the safe choice for risk-averse times, the O.K.-that’ll-do option for Democrats whose chief priority has been finding the candidate best positioned to defeat President Trump. But with Mr. Biden’s setback in Iowa and a slate of flawed competitors beside him onstage on Friday — their shortcomings laid bare in several punchy exchanges throughout the night — the party has been left to consider an unsettling truth.
There is no safe option. And that is starting to feel especially risky.
For a perpetually anxious party, the gathering on Friday supplied an untimely forum to air the weaknesses of several top contenders, aided by the man whose standing has fallen the fastest.
The cost of Senator Bernie Sanders’s progressive health care plans? “He’s unwilling to tell us what the damn thing is going to cost,” Mr. Biden said.
The meager poll numbers among nonwhite voters for Pete Buttigieg? “He’s the mayor of a small city who has done some good things,” Mr. Biden ruled, “but has not demonstrated his ability — and we’ll soon find out — to get a broad scope of support across the spectrum.”
Perhaps most significantly, in the running dialogue that could define the campaign’s coming weeks, the race’s generational fault lines — and the field’s conspicuous absences — came bluntly to the fore. A lengthy discussion of institutional racism proceeded without a black contender onstage, in a primary that once included several candidates of color who pledged to help rebuild the winning Obama coalition. (On Friday, Andrew Yang, the former technology executive, was the only nonwhite candidate who qualified for the debate.)
Mr. Sanders, the septuagenarian choice of the young, acknowledged that the runaway turnout he had hoped for in Iowa had not come to pass. Mr. Buttigieg, the millennial who does best with older voters, appeared to tweak capital veterans like Mr. Biden, Mr. Sanders and Senator Elizabeth Warren when he said that those hungering for the person “with the most years of Washington establishment experience” should look elsewhere.
And in a signal of Mr. Buttigieg’s growing stature in the race in these early states — after functionally tying Mr. Sanders in Iowa, he has inched within striking distance in New Hampshire polls — the former mayor provoked sharp defenses from some of those proud establishment figures.
“This going after every single thing that people do because it’s popular to say and makes you look like a cool newcomer — I don’t think that’s what people want right now,” Senator Amy Klobuchar fired, noting the senators’ work during the recent impeachment trial. “We have a newcomer in the White House now and look where it got us.”
Mr. Biden, in one of several forceful defenses of his long record in Washington, adopted the uncommon political strategy of trumpeting the old ways of doing business, after Mr. Buttigieg urged voters to “leave the politics of the past in the past.”
“The politics of the past, I think, were not all that bad,” Mr. Biden said, spending the night ticking off highlights of the Obama administration and his legislative career.
He was at least “part of the reason,” he said, for the following events in American history: the confirmation of Justices Elena Kagan, Ruth Bader Ginsburg and Sonia Sotomayor to the Supreme Court; the non-confirmation of Judge Robert H. Bork; and the Iran nuclear deal.
He noted his early support for same-sex marriage and his involvement with the withdrawal of troops in Iraq (“I did that”); the Paris climate accords; gun legislation (“I’m the only guy that beat the N.R.A. twice”); and “every major initiative we have had relative to diplomacy.”
Democrats, rarely a tranquil lot this election season, have endured a particularly distressing week. Mr. Trump’s long-anticipated Senate acquittal was dispiriting enough for his critics — punctuated by a series of angry public appearances from the president, news that his approval ratings have climbed and, on Friday, the firing of key witnesses who had testified in the House impeachment proceedings.
In one memorable flourish on Friday, Mr. Biden urged the crowd to its feet to honor one of them, Lt. Col. Alexander S. Vindman, a National Security Council official whom the White House had dismissed earlier in the day.
“Stand up and clap for Vindman. Get up there!” Mr. Biden said. “That’s who we are. We are not what Trump is.”
The fiasco of the Iowa results just four days earlier was a psychological blow the Democrats did not see coming, a self-inflicted mess that instantly shook confidence within the party and seemed to validate Republican taunts that their opponents cannot even be trusted to count their own votes.
This crisis of competence is now the candidates’ to bear, leaving to them the task of convincing voters that the party will be able to come together — and get out of its own way — in time to turn back Mr. Trump. The fallout from Iowa has only exacerbated the wide-scale disdain and distrust that many progressives, particularly Sanders supporters, have reserved for the party leadership.
Still, with success in Iowa and a strong showing in New Hampshire polls, Mr. Sanders has emerged as the unquestioned early choice of the left, outperforming Ms. Warren, who had threatened to eat into his liberal base, and watching with delight as the race’s moderate lane remains a candidate pileup.
Ms. Warren’s campaign has argued that she still has a path, preaching a stay-the-course message and telling reporters that she has the “widest, deepest coalition” in New Hampshire, a state that borders her own.
On Friday, she appeared to take aim at former Mayor Michael R. Bloomberg of New York and perhaps Mr. Buttigieg with a familiar theme: lashing the billionaire class. “I don’t think anyone ought to be able to buy their way into a nomination,” she said, before also knocking “people who suck up to billionaires in order to fund their campaigns.”
Mr. Biden’s post-Iowa adjustments have been more dramatic. In a significant leadership shake-up, Mr. Biden has given effective control of the campaign to Anita Dunn, a veteran party operative, an acknowledgment that major improvements must come quickly if he is to reverse his fortunes.
But no staff reordering can change the profile of the candidate. In person, Mr. Biden has often felt like a contender at odds with his reputation: He was a national-polling leader who teetered through nationally televised debates; a three-time presidential candidate whose experience could not protect him from damaging mistakes; a former vice president who spoke constantly of his closeness with a popular former boss who had not explicitly endorsed him.
For a candidate whose allies had allowed themselves to dream of an incident-free path to the nomination, muscling through Iowa and dominating by Super Tuesday, his early stumbles have been startling. Now, more than three decades after first seeking the presidency, Mr. Biden has staggered into New Hampshire having extended his track record of primary failure, asking voters to believe that he is the safest electoral choice.
And so, the goals of Mr. Biden’s Friday evening were perhaps loftier than they had been at past debates. In a series of uneven performances throughout the primary, he had appeared at times content to grade out with a gentleman’s “B” — good enough to get through the night, if not to put away the field. Now the moment has plainly demanded more.
On Friday, it was a fiery Mr. Biden, whose efforts at soaring oratory can sometimes veer closer to a shout.
He was at his most passionate and to-the-point when discussing matters within his comfort zone: Foreign policy. Legislative accomplishments. Experience. His time in the Obama administration.
When Mr. Buttigieg said at one point in the evening that he offers a perspective “of somebody whose life has been shaped by the decisions that are made in those big white buildings in Washington, D.C.,” Mr. Biden — perhaps inadvertently — appeared to strike at a crucial tension of this primary.
“I don’t know what about the past of Barack Obama and Joe Biden was so bad,” he said, his volume rising. “We were just beginning.”