The evangelical constituency in the US is a political prize fought over by both Republicans and Democrats. White evangelicals are voting Trump by a huge margin – 76 per cent are on his side – while black and hispanic voters tend to favour Clinton. According to Pew, 89 per cent of black Protestants, two-thirds of whom are evangelicals, will vote for Clinton in November.
So endorsements from leading evangelical pastors and opinion-formers are prized, because they can influence the followers of these Christian leaders. "So-and-so thinks Trump is a good guy? Well, maybe he's right."
And so far, Trump is way ahead in the evangelical endorsement stakes. In a smart move, he's also set up a faith advisory board which includes prominent evangelicals. Endorsing him is not a condition of membership, but it lends colour to his claim to be representing them – and muffles any criticisms of him they might feel inclined to make.
Here are some of Trump's evangelical backers.
Wayne Grudem, the Southern Baptist ethicist and theologian, said voting for Trump was a "morally good choice". In an article for Townhall, he admitted that Trump was egotistical, bombastic, brash, had mistaken ideas such as bombing terrorists' families and was insulting and vindictive. "These are certainly flaws, but I don't think they are disqualifying flaws in this election," he said, referring to the probable consequences for conservative causes of a Clinton victory.
James Dobson was a huge coup when he endorsed Trump on July 22. He founded the conservative Focus on the Family organisation and the Family Research Council, both highly influential in conservative circles. He is an outspoken campaigner for traditional views of marriage and against abortion.
Jerry Falwell Jnr is the president of Liberty University and son of one of the founders of the Moral Majority movement. He won notoriety for carrying a gun when he addressed Liberty students after the San Bernardino shooting and advocating "more good people" carrying weapons.
Robert Jeffress, pastor of First Baptist Church, Dallas, has been careful not to say he endorses Trump, but he has arguably done so implicitly. He serves on Trump's advisory board and has said Republicans who refuse to support him are "fools" motivated by pride. Referencing Trump, he said he wanted the "meanest, toughest son of a gun I can find" to be president.
Paula White has also fought clear of an explicit endorsement but is known to be close to Trump and his campaign. According to Politico, the televangelist and prosperity preacher says she has frequently discussed faith with Trump and that his faith is genuine. On the other hand, her influence within evangelicalism may not be great: Southern Baptist leader Russell Moore tweeted: "Paula White is a charlatan and recognized as a heretic by every orthodox Christian, of whatever tribe."
Mark Burns runs a Christian TV network. He has been an active campaigner for Trump and prayed a controversial prayer at the beginning of the Republican National Convention in which he referred to Hillary Clinton and the Democrats as "the enemy".
Jack Graham, pastor of the Prestonwood Baptist megachurch in Plano, Texas, has said he will "champion Donald Trump" after attending a meeting with more than 900 evangelical pastors and activists with him. He said: " "I know that I feel very convinced that it's not just 'Oh, we got to stop Hillary Clinton,' which we do, but that we can champion Donald Trump," Graham said. "I am convinced he is going to make a great president of the United States."
Eric Metaxas is an author, speaker and radio host who has written biographies of Wilberforce and Bonhoeffer. He said: " Not only can we vote for Trump, we must vote for Trump, because with all of his foibles, peccadilloes, and metaphorical warts, he is nonetheless the last best hope of keeping America from sliding into oblivion, the tank, the abyss, the dustbin of history, if you will." A conservative public intellectual, he has been accused of serious errors of fact in his work.
Tony Perkins is the head of the Family Research Council and offered a full-throated endorsement for Trump at the Republican National Convention. The conservative and family values standard-bearer said: "I will be voting for Donald Trump in November, and I will urge my fellow Americans to do the same."
On Hillary Clinton's side there are fewer big names.
Max Lucado wrote a stinging post about Trump entitled Decency for President. However, he has not publicly backed Clinton and wrote last week of a "strange dream" in which she and Trump together "get down on their knees and ask heaven to send mercy to our land".
Deborah Filkes, executive adviser to the World Evangelical Alliance, condemned Trump's behaviour to minorities and women, and said: "Hillary Clinton is the leader who people of faith are looking for and we are praying that Sister Hillary and not Mr. Trump will be elected in November."
Thabiti Anyabwile, pastor of Anacostia River Church in Washington, DC, wrote a blog post for The Gospel Coalition referencing Stalin and Hitler but saying it was necessary to make a choice in a way that "attenuates the evil". He would vote Clinton because she was more predictable, he said.
The lack of enthusiastic endorsements for Clinton encapsulates her difficulty with a constituency to whom she ought to be far more attractive. She is a sincere Christian with vast political experience. However, her relatively liberal position on abortion makes her suspect and her reputation for untrustworthiness, however weak its foundations, makes her an unpopular candidate.
Follow Mark Woods on Twitter: @RevMarkWoods