Into the pale stone wall of the Kennedy Center, above its elegant terrace on the edge of the Potomac river, are carved bold and idealistic sentiments. “This country cannot afford to be materially rich and spiritually poor. To further the appreciation of culture among all the people, to increase respect for the creative individual, to widen participation by all the processes and fulfillments of art – this is one of the fascinating challenges of these days.” Those are the words of John F Kennedy, after whom the US’s national performing arts centre is named. The impulse to build it came from Dwight D Eisenhower; it was given JFK’s name after his assassination; and it opened in 1971, to the music of Leonard Bernstein and the choreography of Alvin Ailey, in the presidency of Richard Nixon. The Kennedy Centre, in short, was designed to be bipartisan, a place of gathering for Democrats and Republicans alike, a proud showcase of the best of America’s dance, opera and music.

For 50 years it carefully trod that line, its board balanced by members of Congress from both sides of the political divide. But it turns out it can take just months to unravel half a century of high-minded purpose.

I have visited the Kennedy Center twice this year – once in the early spring, once in the late autumn. In March, patrons were adjusting to the shock of Donald Trump’s insertion of himself over the organisation – a few weeks earlier he had sacked its Republican chair and had a new, compliant set of trustees vote him in instead. The night I attended, the audience booed the vice-president, JD Vance, at a National Symphony Orchestra concert, which he was attending with his wife Usha, a trustee. The experienced president of the centre had just been replaced with Richard Grenell, an ambassador to Germany under Trump’s first term, a man without any experience in arts administration. Trump and Grenell committed themselves to eradicating the “woke” programming that they claimed had captured this home of Stravinsky orchestral suites and Mozart operas. Eight months on, the performance I attended of Aida by the Washington National Opera was as spectacular and impressive as one might expect. But the place was quieter and more subdued. Now, from the wall opposite the stage door, gazed down portraits of the first and second couples. There was no doubt about who was meant to be in charge.

By this time, ticket sales had, according to a Washington Post analysis, plummeted. Formally loyal patrons were staying away from what many now regarded as a toxic and politicised institution. Productions – notably, the musical Hamilton – had pulled out of the venue. An entire season of classical concerts, run by Washington Performing Arts (tagline, “championing the arts as a unifying force”), had absented itself from the building, having taken a swift decision to stage its recitals and concerts in alternative venues across DC.

Multiple staff members had resigned or been laid off. Sudden terminations included that of the dance programming staff this summer, when an experienced team was replaced by a former ballet dancer who had written to Grenell and Trump offering to help wipe out “leftist ideologies in the arts”. Being a Maga loyalist, or staying silent and toeing the line, appear to be requirements for those associated with the centre. The National Symphony Orchestra now plays the national anthem before its concerts – something that might be done from time to time in Ukraine, a country actually at war, but has an entirely different significance when the arts are being positioned as props in a nakedly nationalist agenda. (See also: the Trump-authorised plans for marking the 250th anniversary of the foundation of the US, which include a sculpture garden of statues of approved “great” Americans.)

The Kennedy Center now regularly feels like a “mortuary”, according to one person who works there, because performances and visitors are so thinned out. The management claims victory by announcing fundraising wins – from what one might call unusual sources, such as a substantial donation from the Kazakh government. Even so, the Washington National Opera, its artistic director told me, is considering leaving the centre because its loyal patrons are unwilling to come and donors are reluctant to offer financial support. Audiences are at times artificially swelled through ticket giveaways: one staff member told me of an all-company email this week offering free tickets to employees for this week’s performances of Handel’s Messiah, a seasonal favourite that ought to be a no-brainer sellout.

The past fortnight has been particularly florid in terms of the Trumpification of the centre. First there was the palaver of the Fifa World Cup draw, an event (offered to the federation without a hire fee) that required the hurried rescheduling of various long-programmed performances, and at which Trump was awarded, absurdly, with the “Fifa peace prize”. Then, a few days later, came the Kennedy Center Honors, the conferring of lifetime-achievement awards on distinguished artists. Previously, honorees have been proposed by an expert committee. This year, though, the president said he had been “98% involved” in the selection, had turned down various “woke” names, and even emceed the event himself, joking as he did so that the place might be renamed the Trump-Kennedy Center. Why stop there, one might ask – why not eradicate JFK altogether? Surely it would be easy enough to erase Kennedy’s high-minded inscriptions from its walls as part of the building’s much-vaunted renovation?

A pushback has begun. A Democrat senator, Sheldon Whitehouse, has written to Grenell outlining concerns about spending, questioning outlandish-seeming hotel costs, “lavish meals and entertainment”, the deal done with Fifa, contracts offered to personal friends, and discounted rentals for political allies, including a conference titled “The Christian Persecution Summit”. (Grenell wrote back denying what he called false accusations.) But pushback or not, there will be a lasting effect on this once great palace of the arts, whatever happens at the next presidential election. It is quick and easy to unravel something, and hard to nurture it back to health – the same goes for so many of the US’s institutions, and for the country itself.

For those in the UK who are tempted to imagine, “It couldn’t happen here,” they should not kid themselves. Nigel Farage and others on the British hard right are already intensifying their pound-shop Trumpism – a new Trumpism that takes inspiration from Viktor Orbán’s reshaping and repression of broadcasting, the media and cultural institutions in Hungary. What has been done at the Kennedy Center should be seen not as a spectacle, but as a warning.