A savage conflict, largely fought underground, is convulsing the Catholic church in the US after a former Vatican ambassador to Washington demanded that Pope Francis resign – a gambit that has not been played in church politics since around 1417.

The ostensible cause is the charge made by the Catholic Archbishop Carlo Maria Viganò, that Pope Francis rehabilitated and used as his adviser on American appointments Cardinal Theodore (“Uncle Ted”) McCarrick, despite being warned that he had a reputation for abusing trainee priests. There are problems with this story. No one now disputes the sexual abuse. When it came to public knowledge earlier this year, the pope stripped Bishop McCarrick of his post as a cardinal. But Archbishop Viganò claims that Pope Benedict had previously condemned Bishop McCarrick to the lesser punishment of “a life of prayer and penance”. Ignoring this punishment is Francis’s supposed crime and complicity. The trouble is that the punishment was entirely secret. Bishop McCarrick carried on as usual. There is even footage of Archbishop Viganò, as ambassador to Washington, hailing him in public as “a man whom everybody loves”.

The US Catholic church is as completely divided by politics and culture as the rest of the country. The Catholic right identifies with the Republican party almost as closely as parts of the evangelical movement do. Its issues are abortion, nationalism, and the suppression of gay rights. It has been recruited to the Republican strategy of detaching social conservatives from the Democrats. It also contains a number of intellectuals, many recruited from Protestant denominations, who see in the apparently timeless and God-given truths of the faith the only defence against the shallow and illusory satisfactions of the consumer society. The Catholic left has a more direct complaint against contemporary capitalism. It is on the side of Latino immigrants, even though many of these are now evangelical Protestants. It regards Catholic teaching on sexuality as possibly inspiring in theory but unworkable and often immoral in practice. Both sides regard the other as heretics who will destroy the church if left unchecked. Neither are nearly as countercultural as they suppose themselves to be. Meanwhile, the church continues to lose numbers and influence in the developed world, something both sides take as proof of the urgency of their diagnoses.

There are signs in this present row that the Catholic right has learned tactics from the political right: the constant harping on stories incomprehensible to the public and unknowable in detail is reminiscent of supposed scandals from Whitewater to Hillary Clinton’s emails. The message is always the same: that the establishment is corrupt and full of liars. In a church gravely weakened by successive child abuse scandals, this cuts through.

Pope Francis has responded with what sounds like passive aggression. In the homily at his most recent mass, he said that “with people who seek only scandal, with those who look only for division, who want only destruction” the best response was silence. In case anyone should miss the point, he said “the father of lies, the accuser, the devil acts to destroy the unity of a family, of a people”. This scandal will of course blow over but the forces behind it remain and make a lasting peace hard to imagine. The convulsions of the end of the liberal world order are shaking the billion-strong Catholic church as well as the rest of us.