Clinton won hands down

Civility went south fast in Monday's debate. Donald Trump lost his composure early, ranting, interrupting (over 20 times) and sniffing. (Under the weather, or out of his comfort zone?) Hillary Clinton started out soft, playing the grandmother card, but quickly escalated to tough talk and occasional sarcasm. It could hardly have gone otherwise. Clinton hit hard at Trump, bringing up his admiration of Russian President Vladimir Putin, his "long record of engaging in racist behavior," his denial at having supported the Iraq war, and his refusal to allow the American people to see his tax returns.

Can Hillary Clinton step out of Bill's NAFTA shadow?

In doing so, Clinton did Americans a big favor: she revealed Trump's limitations. He is simply unable to make those leaps of imagination and generosity necessary to transform from a businessperson to a national political leader. The candidate who claims to do everything big showed the smallness of his thinking tonight. With his off-key rejoinders, he demonstrated repeatedly how he sees everything -- people, properties, cities, and entire countries -- in terms of how they factor into his business and personal universe, which seem to be one and the same. I'll get to Pennsylvania Avenue one way or another, he said tonight, as though the White House and his new Trump hotel are entities of equal importance. Perhaps they really are, in his mind.

Clinton alone demonstrated the composure, wisdom, and broad vision necessary for executive office. She won the debate hands down.

Ruth Ben-Ghiat is a professor of history and Italian studies at New York University, a specialist in 20th-century European history and a frequent contributor to CNN Opinion. Her latest book is "Italian Fascism's Empire Cinema." She supports Hillary Clinton for the presidency.

Raul Reyes: A sad night for 'Sniffles'

Raul Reyes

The reality TV star and businessman who loves giving nicknames earned himself one tonight: "Sniffles." From the beginning through the end of the first debate Donald Trump seemed to have something going on with his sinuses. It seemed a fitting metaphor for a night on which the usual expert showman was seriously off his game. Besides the sniffles, Trump made faces and sighed. He scowled. He interrupted. He took innumerable drinks of water, something for which he used to mock Marco Rubio.

In so doing, Trump lost this debate to a clearly up-to-the-task Hillary Clinton. Either Trump failed to prepare, or his prep sessions did not stick.

The first presidential debate in under 2 minutes 01:57

This is a debate that will likely be studied in college communications, advertising, and gender courses for years to come. Without the benefit of a live audience cheering his one-liners, Trump seemed deflated and not on his best form at all. His constant interruptions of Clinton will do him no favors with women voters. His bragging, in effect, about forcing President Barack Obama to produce his birth certificate will not go over well with black voters. And his rambling answers at times descended into incoherence. In response to a question about cybersecurity, he mentioned that cyberattacks could be coming from "someone sitting on their bed weighing 400 pounds." Uh, what?

Clinton did not let opportunities go by to score points with independents or moderate voters, reminding viewers that Trump once saw the mortgage crisis as a business opportunity, and she discussed race relations in thoughtful terms. Meanwhile, Trump made truly bizarre statements, such as she has been been fighting ISIS for 30 years! and "African-Americans and Hispanics are living in hell, you walk down the streets, you get shot." Note to Trump: Testiness is not a presidential look.

Debate reality check: Does 'stop and frisk' stop crime? 01:29

The fact that at several points Trump was arguing with moderator Lester Holt showed that things were not going his way. In one of the most notable moments of the night, Trump's declaration that he had a much better temperament than Clinton earned spontaneous laughter from the audience at Hofstra University. As Trump might say: "Sad."

Unusual omissions tonight: No mentions of Trump's feuds with everyone from a distinguished Mexican-American judge to a Gold Star family. More glaringly: no discussion of immigration.

Whether viewers agree with Clinton's positions or not, she was able to articulate them in a reasonable and rational manner. She did well, and she knew it. She was obviously ready to discuss problematic issues like her emails. The grin on her face near the end of the debate was evidence that she was aware that she had had a great night. Once you've traveled the world, negotiated treaties, and testified before Congress for 11 hours, she said to Trump with a hint of mockery, then "you can talk to me about stamina." Mic drop. Game over. Tonight at least, Hillary Clinton won.

Jeff Yang: Trump weaved his own hanging rope

Jeff Yang

This was a remarkable moment in American political history. Has there been a prior event in which a candidate has so completely and remarkably demonstrated his unfitness for the presidency, in character, temperament, preparation and aptitude?

Donald Trump's now-familiar pattern of winning debates through sheer bluster and braggadocio was effective when he was facing a gaggle of opponents, all of whom had similar ideologies but less exaggerated stage personas. But faced with a single rival with clearly distinct ideas and experience and a staunchly unflappable attitude, he seemed rude, ignorant, volatile and churlish. Despite pundit assertions that Hillary Clinton had the burden of proof in this debate, the truth is that she simply needed to hold strong and let Hurricane Trump blow itself out. And she did.

5 times Donald Trump was live fact-checked 02:37

Sadly, moderator Lester Holt was a non-presence in the debate. But his inability to restrain Trump proved an asset to Clinton, who spent much of the time leaning back and smiling to herself, knowing that her opponent was weaving his own hanging rope.

Sally Kohn: Trump train derailed

Sally Kohn

Donald Trump's supporters like to refer to his movement as "The Trump Train." Well, tonight The Trump Train went off the rails. Big time.

Admittedly, to many observers, the train was already way off track. Maybe it started the moment his campaign began, when he dismissed Mexican immigrants as "rapists." Or maybe it was when he attacked Sen. John McCain. Or later, when he attacked a Gold Star family. Certainly, many Americans have paid attention to the media's attempts at fact checking -- including one report that Trump only tells the truth 22% of the time, and another that found in five hours of talking, Trump outright lied an average of every 3 minutes and 15 seconds.

Poll: Clinton wins first debate 00:49

But for those who somehow thought, up until Monday night, that Donald Trump might somehow be qualified to be president, Monday's debate was a wakeup call. He seemed like a defensive, petulant bully who could only insult Hillary Clinton and America -- and couldn't offer a single solution, let alone details. He came across as not only dreadfully unprepared for the debate, but dreadfully unprepared to be president. Which is the truth. And it's high time all Americans know it.

But don't believe me. I'm obviously biased. Believe Frank Luntz. In his live focus group of undecided and leaning voters, just six people thought Trump won while 16 said Clinton was the victor. In moment after moment, the focus group preferred Clinton. For instance, Clinton's response to Trump's attack on her stamina scored better than Trump's attack. And Hillary's plan to defeat ISIS actually scored better with the Trump leaners in the group than with the Clinton leaners.

Trump speaks out on taxes, birther movement 03:19

In moment after moment, Hillary Clinton presented a knowledgeable and clear-eyed vision for how to help working families and continue America on the path to security and prosperity. Donald Trump, in contrast, lied, and got defensive. He was petty and insulting, and then lied some more. Lies apparently can only get the Trump train so far. Eventually it runs out of steam.

Hillary Clinton showed herself to be the kind of person you want in the White House. And Donald Trump showed himself to be the kind of kindergartner who should have his train taken away and instead given a timeout.