Photo illustration by Slate. Photos by Scott Olson/Getty Images (2), Alex Wong/Getty Images.

Successfully debating Donald Trump is the hardest thing that should be an easy thing in our world today, right up there with beating Donald Trump in an election with adult voters. In debate after debate after debate during the Republican primaries, Trump showed little understanding of or curiosity about public policy, instigated childish fights with his rivals, and disappeared from the conversation altogether when it bored him. He skipped one debate because he didn’t like Fox News’ sass. In another that he did attend, he bragged about the size of his penis. Never forget that he bragged about the size of his penis in a debate among candidates vying for the United States presidency. And never forget that, either in spite or because of all this, he won the Republican nomination for said presidency and is now polling neck-and-neck with his Democratic competitor, Hillary Clinton.

During the primaries Trump was able to get away with being his unvarnished self. In creating his primary plurality, he hardened for himself a national majority in opposition to him. The gains he’s seen in polling during September have come from both Clinton missteps and a more disciplined operation under new Trump campaign manager Kellyanne Conway, who has tamed her candidate’s feral impulses at the margins. There are even murmurs that Trump is preparing for Monday’s first debate at Hofstra University, which might have less to do with his domestication than with the fact that he is about to go in front of the biggest television audience he’s ever had.

What keeps the Clinton campaign awake at night must be the possibility of Trump passing through this first debate with a calm and poise for which he is not known. The Trump campaign’s hope is to trick people, white-collar white people in particular, into believing that he is indeed calm and poised. Once Trump is onstage and under duress, though, he will be tempted to revert to his nature. Clinton’s goal will be to induce such behavior—to coax out the real Trump, the one who “won” in the primary by losing the majority of the country. Here’s how she can do that.

Ask him to explain pretty much anything.

The large Republican primary field didn’t just help Trump by allowing him to cruise to early victories with relatively modest pluralities. It also helped him in the minute-to-minute unfolding of the early debates. He could get in his insults against Jeb Bush or Rand Paul or some other foil, and then, as the conversation—as it occasionally did—ventured into more substantive policy grounds, he could go into hiding for tens of minutes at a time as, say, Paul and Chris Christie argued about surveillance programs or medical marijuana. The stage will be smaller Monday night, as Trump competes in the first one-on-one presidential debate of his life. There will be no hiding.

It’s not necessarily in Clinton’s interest to turn this into a patronizing quiz show. Voters don’t cast their ballots based on which candidates best trill the rhotic consonants in foreign leaders’ names. But there are things that people expect their presidents to know, and on this count Trump tripped up a few times during the primary debates.

In the Dec. 15 debate held in Las Vegas, CNN guest questioner Hugh Hewitt asked Trump which element of the aging nuclear triad he felt was most urgently in need of an upgrade. Trump’s response was a jumble of nonsense about Iraq and Syria that made clear he had never heard the term, which refers to land-, air-, or sea-based systems for delivering nuclear weapons. That’s not great. But it’s deeper than terminology: It was clear that he had never considered the question of nuclear arsenal maintenance. He did, however, say that, “I think, for me, nuclear is just the power, the devastation, is very important to me.” Indeed, big bomb go boom.

Trump is running strongly against the Trans-Pacific Partnership. (Hillary Clinton claims to be against TPP, too, though no one really believes her.) When asked for even modest details of the trade pact, though, Trump tends to stumble. In the Nov. 10 debate, Trump went on about how “It’s a deal that was designed for China to come in, as they always do, through the back door, and totally take advantage of everyone.” For all of the trade deal’s opacity and complexity, it is indeed not “designed” to allow China to do that. It is designed to corner China into reforming its economy. Rand Paul chimed in after Trump’s spiel to point out that China is not a signatory to the deal, and Trump had little to say in response. The next day Trump and his team retrofitted their version of the exchange to make it sound as if he knew exactly what he was saying and what he meant. This explanation, too, was lacking.

Clinton doesn’t need Trump to name the presidents and prime ministers of foreign countries. What she—or the moderators—could do, though, is ask him to explain the details of any of the policy proposals other people have written up on his behalf. How many weeks of paid leave are offered in Trump’s child care plans? Who would and wouldn’t be covered? Trump could be asked the cost of either his tax or education plan. Even better: What are his tax and education plans?

One of the most effective versions of this model in the primary was when Sen. Marco Rubio, during the Feb. 25 debate, asked Trump to explain his health care plan. This is where Trump went on about “the lines,” referring to selling insurance across state lines, but had little else to offer beyond repetition.

Clinton doesn’t just need to ask him about his own plans. She could ask him to explain anything. How does Medicaid work and how would he change it? What does he dislike most about the Iranian nuclear deal? What’s the latest from Syria? Don’t wander too far in the weeds, but try to find some way to get him to move past the few superficialities he’ll have memorized. Remember: Trump does not know what he’s talking about. Ever. This fact gets obscured from time to time whenever we start talking about Trump pivots and message discipline and the like, as if the problem simply were a lack of grace. And we should be careful to avoid the fallacy so common on the left that politics is about knowing more stuff than the other guy. But the simple truth is that Trump does not understand the basic grammar of the job he’s seeking.

Get him to say something incredibly sexist.

An observation: Hillary Clinton has faced sexist criticisms in her career. You may have noticed this. A twin observation: Donald Trump has dished out a lot of sexism in his career. You may have noticed this, too. One dynamic of the debate, then, is whether Trump will be able to stop himself from making some outward expression of his sexism—a remark, a gesture, anything.

There was one woman in the field of 16 competitors dispatched by Trump en route to the nomination. Though Carly Fiorina posed little threat, Trump was unable to control himself against her. He was unable, as reported by Rolling Stone, to prevent himself from saying about Fiorina: “Look at that face! Would anyone vote for that? Can you imagine that, the face of our next president?!” This was something that he had to say.

Trump did not acquit himself well when that quote was brought up in the (interminably long) Sept. 16 debate at the Ronald Reagan Presidential Library in California. Trump had claimed that by “face,” he meant her persona. Moderator Jake Tapper asked Fiorina to respond to it all. With great poise, she said, “I think women all over this country heard very clearly what Mr. Trump said,” to roaring applause. Trump, to groans, replied: “I think she’s got a beautiful face, and I think she’s a beautiful woman.”

Fiorina did shoot up in the polls after this debate, before the usual combination of additional scrutiny and unsustainable media oxygen sent her back down to the realm of also-rans.

Hillary Clinton has experience in one-on-one debates with male counterparts who express fatally boorish behavior. It will be the test of a lifetime for Trump to make it through one debate without patronizing her similarly; he needs to, though, if he’s to recover some of his numbers among suburban college-educated women, the traditionally Republican demographic that Trump has bled from his wherevers. Don’t let him. Mention some of his sexist remarks. Maybe he’ll keep it together during the debate, and wait until the next day to say something terrible.

Draw out his childishness.

Trump needs more voters coming out of the debate thinking that he’s a properly matured adult, rather than a child. One common trait among children is their inability to manage their passing rages. The proper response here is not for Clinton to respond in kind. She’s not a natural heckler, and when people who aren’t natural hecklers try to meet Trump on his level, they get mauled. Trump is the only candidate who can pull off his brand of childishness. That’s not a compliment.

Sen. Ted Cruz, the best debater in the Republican primary field, demonstrated the best way of managing Trump’s puerility. It was the Mar. 3 debate. Cruz prodded Trump by bringing up a piece of unwelcome information, in this case the pending lawsuit against Trump University, and how he might be on the stand for a “fraud trial” during the general election campaign. This had the instant effect of agitating Trump into sputtering interruption. Cruz was ready.

CRUZ: And with Hillary Clinton …

TRUMP: Give me a break.

CRUZ: … pointing out that he supported her four times in her presidential race.

TRUMP: It’s a minor civil case.

CRUZ: Donald, learn not to interrupt. It’s not complicated.

TRUMP: There are many, many civil cases.

CRUZ: Count to 10, Donald. Count to 10.

TRUMP: Give me a break.

CRUZ: Count to 10.

This shut him up in the moment, which made him even angrier. When it was finally his time to speak, he barked about how he was much higher in the polls. Trump’s polling position in the general election has sharply improved since Labor Day, but hardly into bragging territory. He’ll be without that crutch this time.

Don’t do this stuff.

Don’t think for a second that Hillary can’t blow this. Oh, she can.

Imagine a debate in which Trump keeps his cool. In which he treats Hillary Clinton respectfully and barely even looks at her. In her efforts to provoke him, she comes off as the desperate one. She does the thing where she addresses this generation’s electorate with the last generation’s panders, like invoking 9/11 to defend her lucrative dives into the Wall Street fundraising pool.

Her internal algorithm for divining the proper positions has a tendency to output jibberish—the meeping nonposition of the career pol. Recall her waffling in the 2007 debate about whether she would support drivers’ licenses for undocumented immigrants.

No, she finally answered. Two weeks later.

Clinton hasn’t gotten much better in this respect. She still can’t quite nail down concise answers for either her private email server or what safeguards she put in place against foreign influence-peddling through the Clinton Foundation during her time at State.

She’s not a bad debater. She’s far better in this environment than she is in big auditoriums, trying to rile up the crowds at her rallies. But she’s the sort of non-natural politician who, when she needs to force something, comes off very obviously as someone who is forcing something.

What Clinton needs to remember is that there’s no pressure here. Only some 100 million people will be watching, and the only thing she could blow is the presidential election. If she loses the election, no big deal. America will just be turning control of the world over to a lunatic, ending liberal democracy’s solid post-war run at seven decades. She might faint or make one tremendous, highly replayable gaffe. But again, the only consequence there would be the end of the West. It’s fine. It’s fine. Everything’s fine.