Before the president’s last, best chance to change the trajectory of his re-election bid, his mandate on Thursday evening was at once clear and complicated: Be less like Donald J. Trump.
It can be said that he tried, by his standard. He succeeded at various points in acting like the type of person he claims to disdain: a typical politician in a debate. He spoke with an inside voice while saluting his own pandemic response. He interrupted far less. He thanked the moderator for letting him chime in and did not sound sarcastic while doing so.
And it is far from certain that he helped himself enough anyway.
Swiveling all night between heeding the advice of allies who have pleaded for uncharacteristic discipline and succumbing to impulses that can still consume him as he faces down an opponent he cannot process losing to, Mr. Trump stood before the electorate a candidate in conflict at his late campaign hour.
If Mr. Trump appeared to recognize that the debate represented his final mass audience less than two weeks before Election Day, he also showed the limits of even a more finely calibrated executive performance.
In an election that Mr. Biden’s team has sought to frame as a referendum on the incumbent, particularly his handling of the coronavirus — an endeavor that Mr. Trump has often made quite straightforward for his rival — it was the president who entered Thursday night with more work to do, given the national and battleground state surveys showing him behind.
At times, his answers seemed tailored explicitly with this deficit in mind, targeted at groups with whom he must improve his standing, like seniors, whom he pledged at one point to “protect” four times in a matter of seconds.
But in a moment of relentless national upheaval, manifesting in protest, public health crisis and immense financial turmoil, Mr. Trump also could not help but accentuate the most essential qualities of his tenure on Thursday, reverting to fits of magical-thinking-aloud and grievance-stuffed nonrestraint.
He set off on an extended meditation — most likely to resonate with only dedicated consumers of right-wing media — on whether Joe Biden’s nickname was “the big man” as it related to his son’s business dealings. He dwelled on “the emails, the emails, the horrible emails” with conspiratorial repetition.
He invoked Abraham Lincoln to praise his own contributions to Black Americans.
He specked his virus defense with an aside that “we can’t lock ourselves up in a basement like Joe does,” before nodding at purportedly shadowy sources of Biden family wealth. (“He’s obviously made a lot of money someplace,” he said.)
The president’s opponents like to say there is only one Mr. Trump, and his advisers like to describe a different one: compassionate in private, they insist; altruistic in nature; brawling only when the task dictates as much.
Too often — and despite his best efforts on Thursday — this latter case has tended to collapse in a hail of misstatement and self-congratulation.
He can resemble a chef with one dish, a golfer with one club in his bag — regardless of what the next stroke might require — and a propensity to blame his caddie for the attendant result.
If voters reject him next month, this will be the chief reason: The 2020 campaign is different, and Mr. Trump is not.
He still focused extensively Thursday on often unsubstantiated allegations against his opponent’s son, defying some Republican allies who have counseled that the attacks connect little beyond the conservative echo chamber where Mr. Trump is already beloved.
He still made virtually no attempt to outline a comprehensive second-term agenda that might appeal to any remaining political fence-sitters — to the extent that there are many left, in an election where many millions have already voted and most others are largely set in their views, according to polling.
Of course, political pliability was probably never going to be a prominent feature in a contest between two proud men in their 70s. Mr. Biden likewise demonstrated on Thursday that he is very much the candidate that voters have come to know, for good or ill, across the decades: a creature of a bygone Washington, prone to throwback references, never entirely smooth.
He spoke of “Bidencare” and made a curious allusion to Hitler. He strained to supply a compelling rebuttal to Mr. Trump’s charge that he has been around Washington for almost a half-century to little effect.
Mr. Biden was often at his strongest pressing Mr. Trump on his stewardship during the pandemic, suggesting the president did not have the capacity to evolve in the job.
“He says we’re learning to live with it,” Mr. Biden said of the virus. “People are learning to die with it.”
In an exchange about immigration, Mr. Biden highlighted the 545 children who were separated from their parents at the border, and whose parents cannot be located. “It makes us a laughingstock, and violates every notion of who are as a nation,” Mr. Biden said.
Mr. Trump’s retort was to claim the children are “well taken care of,” and then to focus on the cages that have been used to hold them. “Who built the cages, Joe?”
A businessman who has long specialized in setting Houdini-like traps for himself and then trying to escape, Mr. Trump appeared mindful that this is almost certainly the last time he will ever be on a debate stage. In 2016, he managed to stay relatively disciplined for the final 10 days of the race, something his advisers have lamented since the disastrous last debate.
And if he was not his most unruly self on Thursday, he also remains a man who believes firmly that a refusal to modulate is part of what delivered him to his position in the first place — reason enough, supporters say, to be reminded that this race is not yet over.
Through essentially his entire professional life, the president has delighted in making others adjust to his tics and whims, secure in the knowledge that if history was instructive, everything would more or less work out for him anyway.
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He created the impression of business success by insisting, as loudly and frequently as possible, that he was successful at business. He flattened campaign precedent with gleeful name-calling and race-baiting and was rewarded with the presidency. He faced impeachment after encouraging a foreign government to investigate a rival and was, in his estimation, thoroughly vindicated when Senate Republicans declined to expel him from office.
Even the debate rules on Thursday were an exercise in adapting to Mr. Trump and not the other way around: The candidates were muted for their counterpart’s opening answers to each topic, given Mr. Trump’s fire hose of interruptions the last time.
Such guard rails were only ever going to curb him so much. Mr. Trump had made clear that he was going to spend a portion of the night hammering Mr. Biden over his son’s business ventures, the subject of fevered attention (and more than occasional misinformation and misleading innuendo) on the president’s favored media outlets in recent days.
The strategy presented perils for both candidates. Mr. Biden has been known to grow flustered when challenged on matters of family, lashing out not only at opponents but also at members of the news media who question whether his son Hunter leveraged the Biden name for personal gain.
But there is little evidence that the approach has much helped Mr. Trump with the voters he needs: seniors, suburban women, those disinclined to share the president’s interest in the Fox News prime-time lineup.
Mr. Biden is also often at his most sympathetic when talking about his personal history, rife with tragedies like the car crash that killed his first wife and baby daughter in 1972 and the death of his son Beau from brain cancer in 2015.
Discussing Hunter, who has struggled with addiction, the former vice president has often appended a pointed descriptor: “my surviving son.”
Mr. Trump was undeterred, as ever.
For days leading up to the debate, he bypassed formal preparation but heard from a core group of advisers conveying a singular message with varying degrees of urgency: Control your temper. Do not talk over Mr. Biden. Do not come off as angry. They raised with him issues they believed voters wanted to hear about, including the economy and the competitive threat of China, in keeping with persistent Trump campaign insinuations that any foreign contacts by anyone should be examined.
But inevitably, Mr. Trump is liable to return to the subject that most grabs him: himself, and how unfairly he feels he is being treated.
The first debate appeared to hurt his cause not simply because Mr. Trump could not resist talking over Mr. Biden. It was, more precisely, a very public window into the version of Mr. Trump that led the former White House counsel Donald F. McGahn II to call him “King Kong” — the version that aides have long argued is a figment of the news media’s hyperbolic imagination.
That initial debate spectacle underscored what some people who have known Mr. Trump for years have said privately: that his volatility and anger do not wear well on people.
In this second night of what was supposed to be a three-debate run — the president’s own bout with coronavirus and his refusal to debate virtually doomed another — Mr. Trump was less openly hostile.
But he still made the case that five years into his career in political debates, he is a different kind of leader, hoping to run as an outsider even after four years in office.
“It’s all-talk-no-action with these politicians,” he said in one exchange.
“I’m not a typical politician,” he said in another.
He was just trying to play one on television, in moderation, for at least one night.