He has lost the Catholics, the foreign policy isolationists and the millions of people affected by ICE’s immigration raids. But Donald Trump is still counting on the goodwill of one powerful constituency of American voters, to whom he appealed this week by reading a passage from the Bible urging people to repent their “wicked ways”. A lot of thoughts spring to mind in relation to this, but at the very forefront, one question: do the US’s evangelical Christians, who overwhelmingly support Trump, have a red line and if so, can they find it with both hands?

I’m stating the obvious but it’s worth raising again, if only to boggle at the sheer shamelessness of a religious community that has thrown in its lot with Trump: how on earth do the evangelicals work out the maths on this? Let’s remind ourselves of the facts; that the president treating us to a section of the Old Testament as part of a week-long, continuous public reading of the Bible, from Genesis to Revelation – separation of church and state, anyone? – is the same president who has, variously, been found by courts to have falsified business records, as part of a hush-money payment scheme to a porn star, Stormy Daniels, and sexually abused and defamed E Jean Carroll. As the president intoned to camera in the Oval Office on Tuesday: “If my people, which are called by my name, shall humble themselves, and pray, and seek my face and turn from their wicked ways, then will I hear from heaven, and will forgive their sin, and will heal their land.”

That particular passage is from 2 Chronicles 7:14 and was reportedly chosen for Trump – whose familiarity with the text, we must assume, is patchy – by organisers recognising its popularity among Christians as a political as well as spiritual call to action. We can also assume that the president approved the selection from a short list of options and what I love about the choice is that it comes hard on the heels of his other, recent engagement with Christianity in a way that looks to me a lot like doubling down. It’s very him, isn’t it? Ten days after sharing an AI-generated image in which Trump appeared as a Jesus-like figure healing the sick, here he is delivering a Bible passage that involves taking on a first-person delivery of God’s word. (By contrast, other participants, for example the actor Candace Cameron Bure, read “then the Lord says”-type passages from Genesis.)

Playing second fiddle to another authority is not Trump’s style, of course, and we wait with bated breath to see whether his co-participants in the stunt, including senator Ted Cruz, the defence secretary, Pete Hegseth, and the governor of Texas, Greg Abbott, have been permitted similar licence to channel God’s word in the first person or are relegated to the I’m-just-the-messenger bits.

More interesting to me is how this performance of Trump’s lands with its intended audience. We already know that, among Christian Americans, the Catholics are having a wobble about Trump, which should concern him. Catholics are swing voters who, by a small margin, backed Biden over Trump in 2020 and in a recent poll appeared to be swinging away from him, with support dipping below 50%.

Evangelicals, by contrast, have no moral leader with the authority of the pope to guide them. They are much more solidly and implacably pro-Trump, not least because he put through their agenda to restrict abortion rights by delivering a rightwing majority to the supreme court. They also appear to be more politically organised in the US. The organiser of the America Reads the Bible event is someone called Bunni Pounds, and you will take from that whatever passing enjoyment you may get. Pounds has been labelled a “visionary” by Fox News, and as well as running Christians Engaged, which organised the event, runs something called the Family Policy Alliance, a lobby group that promotes exactly the kind of policies you think it does.

According to Pounds’s organisation, the point of America Reads the Bible is to encourage a “return to the spiritual foundation that has shaped our country”. A mission, you might imagine, would be better achieved by the country not starting an unnecessary war, deporting American citizens or cancelling foreign aid to cause the deaths of an estimated 600,000 people worldwide. On the other hand, if a convicted felon reading a passage from the Bible makes you feel closer to God, then all one can say is good luck to you.

• Emma Brockes is a Guardian columnist