One of the most interesting and important developments in the American culture wars, which is to say in American politics and self-understanding, is playing out inside the major Christian groupings there: evangelical Christianity and Roman Catholicism. The Southern Baptist Convention, the largest fundamentalist grouping, has been roiled by the discovery of a sermon in which Paige Patterson, one of its leaders, boasts that he counselled an abused woman to stay with her husband even when she came to him with two black eyes. Almost 3,000 Southern Baptist women signed a letter demanding that the 75-year-old Mr Patterson lose his job as head of a seminary.

For the last 30 years, the alliance between Catholics and white evangelicals has been an enormously powerful force on the right of American politics. It was based around a common opposition to abortion – a cause to which evangelicals came relatively late – and a wider suspicion of feminism. Apart from that, the two groups have little in common demographically, culturally and even economically. The economic model of American evangelical Christianity has been fantastically successful, based around marketing, merchandising and vigorous competition between preachers for congregations. But when you adopt the methods of the entertainment industry, you will also imbibe some of its values. One result has been the growth of megachurches where the American flag is far more conspicuous than the cross; another is the growth of the “prosperity gospel”, which teaches that the rewards God wants for his followers are to be obtained in this world. The big names of that world, such as Paula White, the thrice-married woman who counsels President Trump, were reality stars before the Kardashians, showing off their wealth as evidence that God blessed them.

At the same time, the organised Catholic church has been ageing and shrinking. It has maintained a degree of intellectual prestige and self-confidence, but congregations have melted away, so that former Catholics could now form the third-largest religious grouping in the US. The scandal-battered clergy is split into liberal and conservative parties, both believing that they are more Catholic than the pope. Only an influx of Hispanic immigrants maintains the church on the ground. But this threatens any alliance with the white evangelical movement. That has become increasingly racist in the last 30 years. It has set its face against immigration as it has against homosexuality and climate change. President Trump is forgiven all his lies and adulteries because he so clearly stands for white supremacy. But when he loses power, the fundamentalists will, too. Their literally patriarchal attitudes to women have already lost the younger generation. Conservatives used to warn that liberals who married the spirit of the age would be left as widows. It is a historic irony that this will be the fate of American conservative Christianity.