On Instagram, that post, in which she signed off as a “childless cat lady” (a response to J.D. Vance’s sneering jibe at leading female Democrats), has been liked more than 11 million times. But did it shift the dial in any way? Maybe. But not in a way that helped Harris.

According to polling site YouGov, before her endorsement, “75 per cent of Democrats and 43 per cent of Republicans viewed Swift favourably”. After it, “79 per cent of Democrats but only 26 per cent of Republicans like Swift”. In other words, it was welcomed by those already likely to support Harris but had the opposite effect on those who were not.

This week, Harrison Ford – who played a president in 1997’s Air Force One – urged people to back Harris and running mate Tim Walz. “These two people believe in the rule of law,” Ford intoned gravelly and gravely. “They believe in science. They believe that when you govern, you do so for all Americans, they believe that we are in this together. These are ideas I believe in. These are people I can get behind.”

Like many throwing their weight behind the Harris campaign, his was an appeal to ideals and the big ideas that underpin the American dream. But for people struggling with cost-of-living pressures, these abstract concepts hold less sway than those cushioned by Hollywood pay cheques might imagine.

According to exit polling conducted by CBS, 69 per cent of Trump voters believe the US economy is in bad shape (compared with 29 per cent of those who voted for Harris). Only 24 per cent of all voters believe they are better off financially than four years ago, while 45 per cent think things are worse. White voters without a college degree backed Trump by 65 per cent, to 34 per cent for Harris.

None of this proves definitively that celebrity endorsements worked against Harris. But it does suggest they did little more than make those already predisposed to her feel in good company. And they might have confirmed for others the view that she did not speak for them and their concerns.

It’s not as if Trump didn’t have celebrity supporters. Kid Rock performed for him, Joe Rogan’s podcast gave him three hours, and Elon Musk poured millions into the campaign and repeatedly endorsed him.

Of course, Trump is the highest-profile celebrity in the US. He may be loathed in New York, where he made his name and (questionable) fortune, but to those flyover states, he is the man who burst into orange-hued life on the reality TV show The Apprentice.

In the end, it’s not celebrity endorsements per se that worked against Harris. It’s that the celebrities spoke for a set of values – idealistic, egalitarian, broad-minded – that did not resonate with a great swath of Americans. And they did so from a position of economic and educational privilege to which they could not relate.

Trump and his backers, meanwhile, parlayed a myth of self-made resilience and individualism, and a distrust of outsiders and authority. To the many Americans feeling the pinch and looking for someone to blame, that rang much truer than any celebrity endorsement.