In their first head-on confrontation of the presidential campaign, Hillary Clinton left Donald Trump bruised in an encounter that underscored questions about his temperament and preparedness.
The two candidates clashed for 90 tense and combative minutes, seeking to sway a race that was nearly tied prior to the debate.
From the opening moments, Ms. Clinton, the Democratic nominee, and Mr. Trump, her Republican rival, offered starkly divergent views on the state of the country and the qualities required in its next leader.
Ms. Clinton launched a series of stinging rebukes of Mr. Trump, suggesting he was unfit to be president by virtue of his character. Mr. Trump, meanwhile, portrayed Ms. Clinton as the embodiment of the status quo and tried to hold her responsible for the policies of prior administrations.
Monday's debate was perhaps the most important date on the campaign calendar other than election day itself. It offered a window into how the two candidates plan to fight the closing weeks of the presidential contest and how they might approach the two remaining debates.
It was a spectacle that pitted Ms. Clinton, the first woman presidential nominee for a major party and a former U.S. secretary of state, against Mr. Trump, a real estate magnate and reality television star who has broken every norm of presidential campaigning.
Some commentators had dubbed the debate the Super Bowl of politics: It was expected to draw an enormous audience, possibly eclipsing the prior record of 80 million viewers set in 1980 when Republican Ronald Reagan squared off against Democratic President Jimmy Carter.
Despite expectations that Mr. Trump would moderate his style for his first face-off with Ms. Clinton, he emerged almost as belligerent – if not quite as outrageous – as usual. He interrupted Ms. Clinton numerous times as she spoke and also tussled with the moderator, Lester Holt. As the debate wore on, Mr. Trump appeared to lose some of his composure, giving rambling answers in a hectoring tone.
Ms. Clinton's extensive preparation for the debate bore dividends. She calmly noted that Mr. Trump had refused to pay tradespeople working on his real-estate projects, failed to release his tax returns and built his political career on a "racist lie" – the conspiracy theory surrounding President Barack Obama's birthplace.
The two candidates sparred not only on questions of temperament and character, but also tangled over differences in policy – on trade, on easing racial tensions and on foreign affairs. Ms. Clinton repeatedly called her opponent's policy prescriptions "trumped-up trickle-down economics." Mr. Trump suggested that Ms. Clinton was complicit in the loss of American industrial jobs, in part due to the North American free trade agreement approved by her husband, former president Bill Clinton.
The debate was punctuated by several memorable exchanges. At one point, Mr. Trump decried the fact that the country's national debt has grown over Mr. Obama's tenure even as some crucial infrastructure remains outdated.
"We owe $20-trillion [U.S.] and we're a mess," Mr. Trump said. "It's been squandered on so many of your ideas," he added, addressing Ms. Clinton. "Maybe it's because you haven't paid any federal income taxes," she countered wryly.
One issue for Mr. Trump is that during the debate, he trafficked in a series of easily checked falsehoods. Mr. Trump denied that he ever called global warming a Chinese plot (he did); he also denied that he ever called pregnancy "an inconvenience" (he did). Such statements can serve as fodder for future attacks by Ms. Clinton, as will his assertion Monday that it's "smart" not to pay taxes – a sentiment few Americans are likely to appreciate.
Mr. Trump's best moment came when he pounded Ms. Clinton on her track record on trade agreements, said David Kochel, a Republican strategist who worked for Jeb Bush and Mitt Romney on their presidential campaigns. But Mr. Trump later became defensive and petty when discussing his business record, Mr. Kochel said. Ms. Clinton "successfully got under his skin."
Both candidates entered Monday's debate eager to seize the opportunity to persuade undecided voters and galvanize their existing supporters. In the past, debates have only rarely proven to be turning points in presidential campaigns. But the unique nature of this race and the widespread misgivings about both candidates may amplify the impact of the debates in this election.
Several recent polls indicate that the race is now too close to call. With just six weeks until election day on Nov. 8, Mr. Trump has eaten into Ms. Clinton's formerly commanding lead. According to the website FiveThirtyEight, which produces an election model based on an aggregate of national and state-level polls, as of Monday Mr. Trump had a 48 per cent chance of winning, compared to a 52 per cent chance for Ms. Clinton. That's his highest probability of victory since the end of July.
Much of the speculation prior to the debate focused on Mr. Trump's performance. He has shown that he can campaign in two distinct modes: a full-throttle version where he delights in his own unpredictability and lobs insults at his opponents, and a lower gear where he is more restrained, sticks to a teleprompter and offers something resembling concrete policy proposals.
It was not clear which of the two styles would dominate on Monday. In the end, he opted for some mixture of the two. He was vehement in his delivery, but he did not enter the kind of territory he sometimes ventures into in his rallies. That combination, however, may mean that he did not meet his major challenge in the debate: to persuade Americans that he is capable of being presidential.
For Ms. Clinton, the debate offered an opportunity to bounce back from a challenging stretch, during which she took a brief pause to recover from a bout of pneumonia. While many voters consider Ms. Clinton competent and experienced, some have persistent concerns about whether she is trustworthy or likeable. Monday presented a chance to assuage such doubts.
As much as the debate was a test of the two candidates, it was also a high-wire act for the moderator, Mr. Holt of NBC. Ms. Clinton's campaign had called on Mr. Holt to play an active role in fact-checking statements made during the debate, given Mr. Trump's penchant for untruths. Mr. Holt did take on that role at times, pushing back against Mr. Trump in particular in his characterization of his record and positions.
At Hofstra University in Long Island where the debate was held, intense security measures were in place in the hours leading up to the event. Within the secured perimeter, there was a carnival-like atmosphere as hundreds of university students visited the giant stages set up by major television networks.
Kyle Mas, a 19-year-old sophomore from New Jersey, said he was watching the debate in the hopes of seeing something to redeem his faith in the presidential race. "It doesn't feel like an election so far," he said. "It honestly feels like it's a debate on Twitter – it's just people yelling at each other." Mr. Mas is leaning toward supporting Gary Johnson, the Libertarian Party candidate for president.
For the large cohort of Clinton supporters on campus and the smaller group of Trump enthusiasts, the debate will have little impact their votes. Matthew Corbett, 20, said he was fully behind Ms. Clinton. For him to switch now, "She would have to change all her views, say sexist and racist things, and promise to build six walls," he said, in an ironic reference to Mr. Trump's promise to erect a barrier along the U.S. border with Mexico.