Now that Kamala Harris has handily dismantled Donald Trump in a presidential debate, one question leaps to the fore: What took so long?

For all the credulous pundit lore that’s accumulated around him, Trump has never been an accomplished debater. In his prior performances, he’s leaned into stock apocalyptic MAGA rants, taunting nicknames, and errant conspiracy-mongering. Even as President Joe Biden imploded before a gleeful Trump in the first 2024 debate, Trump served up many of the same hoary, bogus claims that marred his performance against Harris. Then, as now, he claimed that the January 6 insurrection was a mostly peaceful gathering of concerned patriots and that whatever mayhem took place was Nancy Pelosi’s fault. In both debates, he baselessly asserted that Democrats supported the right to terminate pregnancies into the ninth month and to murder delivered babies. In June, he also depicted immigrants as a murderous and mentally ill threat to the fabric of the country—though he hadn’t yet amplified the fascist-authored libel about Haitian migrants eating kidnapped pets, as he did Tuesday night.

None of this was new. Past Trump debate lowlights include his dog-whistle callout to the white nationalist Proud Boys to “stand back and stand by” in response to the question of whether he would distance himself from the group—a message they took to heart come January 6; his announcement that he might have to jail Hillary Clinton for vibe-inflected abuses of a private e-mail server; his ludicrous effort to blame Clinton for his own yearslong racist crusade to delegitimize Barack Obama’s citizenship. This is all to say nothing, of course, of the broader lies that function as the taken-for-granted background in Trump’s campaigns, such as his nonexistent opposition to the second Iraq war, his never-serious pledges to revive American manufacturing, and of course the vast litany of asides touting his bogus genius as a deal-maker and a businessman. The breathtaking volume and range of lies Trump has aired out on debate stages over the past nine years bear testimony to the broken state of, well, everything—our public discourse, our media, our political parties, and our basic sense of what the truth might be.

Which is also why Harris’s efficient, targeted exposure of Trump’s desperate falsehoods was more than a testimonial to her preparation for the Philadelphia debate and more than a vindication of her much-touted stature as a prosecutor facing off against a low-grade criminal grifter. In repeatedly goading and baiting Trump into higher levels of self-humiliation, Harris served up a reminder of how thoroughly Trump’s gaseous mendacity relies on elite-media and political-class complicity.

By invoking early on the played-out spectacle of the Trump rally—the foundational article in the media’s myth of Trump’s status as a tribune of a forgotten America—Harris set Trump up to reprise the rants about his own rally-crowd size and the supposed fake and leased composition of Harris’s rallies. In Trump’s addled inner monologue, this is all clear testimony to his unanswerable strength in charisma, but channeled into a defensive debate reply, it came off as delusional—and pathetic. The same dynamic held throughout the evening. Harris exposed the phony heroic narrative Trump trots out about the Dobbs decision by mocking his own rhetoric, showing how no woman could remotely be understood as “wanting” conditions that jeopardize her health, her future reproductive options, and her basic access to affordable and life-saving medical care. Amazingly, Harris was even able to best Trump on the Biden administration’s withdrawal from Afghanistan—a stab-in-the-back fable that was front and center at the Republican National Convention this summer and fueled the Trump campaign’s obscene photo-op at Arlington National Cemetery.

Behind the baiting tactic, though, is a psychological insight that’s eluded past Trump rivals: The best way to fluster and derange narcissists is to strike at their most cherished asset—their bottomless vanity. That was the reasoning behind one of Harris’s most direct assaults—her depiction of Trump as a vainglorious and “weak” leader on the global stage, someone whose own senior military regarded as “a disgrace” and who could be readily manipulated by other strongman leaders with “flattery and favors.” Just like the specter of bored and exhausted MAGA followers decamping from his rallies early, this image of Trump as a feeble and easily deceived laughingstock of a statesman was calculated to get him to sputter in rage and incomprehension—and it worked. Trump’s reply began by citing the admiration of Hungarian President Viktor Orbán, a master of election-rigging and dissent-quashing in his own illiberal democracy. He then proceeded to rant some more about the absent Joe Biden, and offered up this “little secret” about Biden’s relationship with Harris: “He hates her. He can’t stand her.” OK, then—nothing disgraceful to see here!

This one weird trick sealed Harris’s victory in Tuesday’s debate, though of course there were other contributing factors. Trump is showing signs of continued cognitive decline, with outbursts and delusional riffs that are extreme even by his usual standards. And ABC moderators David Muir and Linsey Davis did actually manage to push back against at least some of Trump’s most outlandish claims in real time. (This led, predictably, to outraged cries from the MAGA faithful, and the candidate himself, that the proceedings were rigged in Harris’s favor—a plaint that overlooks the basic truth that if you resent fact-checking interruptions, it’s probably a good idea not to lie so much.)

Harris’s successes on this front stand out against the ripostes that Biden and Clinton tried against Trump in their own marquee debates. True to their own political worldviews, Trump’s past Democratic rivals professed horror at the Republican candidate’s transgressions against sacrosanct (small-d) democratic norms. But it does little good to call out trespasses against the rules when you’re facing a candidate and a political movement that thrives on choreographing outrage and exalting demagogic power over the niceties of good governance.

Shaming is never a popular political reflex—it serves mostly to assure the shamers of their own enlightened virtue, while opening up frontiers of ridicule for the norms transgressors to cavort in. (See for just one instructive case in point, Hillary Clinton’s “basket of deplorables” gaffe; for a more extended crash course, see her entire neoliberal ideology.) But humiliation is something else altogether; it reduces your rival’s pet obsessions and outbursts to sad and involuted opera-bouffe arias. It also drives home the pathological depth of an opponent’s self-involvement. How else can a discussion of rally crowds segue into the shouted refrain “THEY’RE EATING THE DOGS”? The other proof of Harris’s successful strategy is that one traditional metric of debate performance—the time each candidate gets to speak—didn’t matter. Trump spoke for more than five minutes longer than Harris did, and only managed to dig deeper and deeper holes for himself.

There are still two months for the balance of the election to play out, and bitter experience has taught us that all sorts of calamities and unforced errors could still tip the playing field back in Trump’s favor. But for now, Kamala Harris has given us all an invaluable lesson: To defeat a narcissist, call him weak and let him talk.