The oddest thing about this — apart from the ongoing sense of history happening in real time — was the lightning speed of the adjustment. It was like looking at a Magic Eye picture or a drawing by MC Escher. Superficially, nothing about Kamala Harris had changed since her abortive run for president in 2020. She was still prone to moments of awkwardness. It was still unclear entirely where her politics lay. 

Held up against the drama of Biden’s agonising exit, however, Harris’ relative youth, energy, and sheer coherence made one want to clap for joy. For reasons that, four years ago, made many of those on the left suspicious of Harris, the 59-year-old suddenly looks a lot like the perfect candidate to fight and defeat Donald Trump.

Certainly, Trump’s team caught this vibe and the scramble to counter it has been pure comedy gold, featuring a lot of people running around trying to find bad words for a lady politician. Within days of Harris’ ascent, Trump was calling her “crazy”, “nuts” and “dumb,” an auto-response that even his supporters at the back might be starting to twig is a generic line of attack. 

Trump’s surrogates, meanwhile, floundered in similar style. When John Kennedy, a Republican senator for Louisiana, referred to Harris on Fox News this week as “a bit of a ding-dong”  — American for silly woman — the remark was so embarrassing that even the Fox host felt obliged to push back.

These attacks will inevitably narrow and personalise. But on the evidence of the first 10 days of Harris’ candidacy, the Republican machine is struggling to find a workable way to undermine her. 

JD Vance, a man so palpably unappealing that he seems to have spooked even those who think that Trump is a good thing, had this week to defend remarks he made several years ago attacking Harris for not having children (she is the stepmother of two). There are circumstances in which this kind of mockery still works, but it doesn’t work here, and Vance, at 39, looked properly absurd — like a Victorian hologram poised to break out the word “spinster” — for making a song and dance about motherhood.

Among the reasons these approaches don’t land is the profile of Harris herself. Trump’s go-to when facing a female opponent is always, in the first instance, sexual humiliation. 

He did it with E Jean Carroll (“not my type”) and, even more astonishingly, with her lawyer, who while taking his deposition at Mar-a-Lago in 2022, was informed by Trump: “You wouldn’t be a choice of mine either, to be honest with you.” Trump’s subtext with Hillary Clinton was she’s your frumpy ex-wife, and he cast Elizabeth Warren as a desiccated librarian.

However, the cat lady thing doesn’t work with Harris. Per Trump’s own metrics, she’s simply too young, too polished, too far above him in the rankings in which he puts so much store and habitually uses to denigrate women. In this, Trump’s own value system, it’s Trump himself, two decades her senior, who looks like the guy on the couch picking crumbs from the creases of his vest. 

Harris looks like his worst nightmare: A former attorney general of California in heels, slick, telegenic, with a corporate image and politics that have been largely in the centre — so that when Trump says “She is a radical left lunatic who will destroy our country,” he sounds ridiculous.

And while Harris has, to date, not been a particularly assured politician, she seems to know instinctively how to handle Trump. With a smirk that does more work than all of Clinton or Warren’s earnest attempts to debate him, Harris meets Trump at the demotic level and states the bleeding obvious: “These guys are weird.” It works because it’s true, but also because she’s doing the thing Trump hates above all other things: She’s laughing at him.

• Emma Brockes is a Guardian columnist