In early 2016, the then-Republican front-runner – a reality TV star with a penchant for women and gambling – gave a stirring talk at a Christian college in Iowa.
“I will tell you, Christianity is under tremendous siege,” Donald Trump, not yet the 45th president of the US, roared.
Mr Trump whipped the religious crowd into a frenzy by wondering aloud why Christians – the majority in the country – were not at the forefront of political life.
“Christianity will have power,” he vowed.
On election day, nearly 81 per cent of white evangelical Christian voters put aside any private moral beliefs and helped bring Mr Trump to the White House. In return, he brought about the beginning of a Christian America.
First, he packed his administration with evangelicals: Vice President Mike Pence, Secretary of Education Betsy Devos and Secretary of Housing and Urban Development Ben Carson.
He pursued policies that would appeal to the broadly conservative community. Most Evangelicals oppose divorce, gay marriage or abortion. They want to ensure America is a Christian nation – despite its founding principles never explicitly making it so.
They want to secure a conservative Supreme Court to protect these ideals and Mr Trump delivered in the shape of conservatives Neil Gorsuch and Brett Kavanaugh, who both got a lifelong spot on the highest court in the land. He also appointed a number of conservative pro-life federal judges.
The danger, Democrats and centrists say, is this legal shift could jeopardise precedents such as Roe vs Wade, the landmark 1973 Supreme Court ruling that deems state restrictions on abortion unconstitutional.
Away from domestic conservative policies, Mr Trump had another card in his pocket: Israel.
By moving the US Embassy to Jerusalem, he played to the Christian Zionist movement.
It is their belief that the return of Jews to the Holy Land – and thus the Nakba of 1948 and the subsequent occupation of the West Bank and Gaza – are in accordance with biblical prophecy. The gathering of the Jews in Israel, they believe, will bring about a Second Coming of Christ.
And there is no denying that the evangelical vote is significant.
More than 25 per cent of US Christians identify as evangelical, meaning they believe the Bible has the ultimate historical and moral authority.
More than 76 per cent of evangelicals are white and voter turnout is high.
But the Christian vote in America is a curious one.
The heartland farming families have deep traditions, sexual morality and family values. They have white-steepled churches, Fourth of July picnics, Memorial Day parades and the Bible.
But they also feel alienated. Far from intellectual East Coast or liberal California, there is rural Middle America. Issues such as the Black Lives Matter protests have sparked concern.
And now the question for many is whether Mr Trump – who may deliver on policy but rarely goes to church or outwardly espouses specific religious sentiment – is the man for them again in 2020?
Mr Trump’s political strategy so far seems rooted in sowing discord, believing that dividing the country will bring him more votes. He has tried to play up his own law and order credentials amid riots and warned Democrats will disband police and hang traditional values out to dry – neither of which are, as yet, listed among Mr Biden’s campaign pledges.
Despite their firm “family” values, the evangelicals voted for the twice-divorced, womanising Mr Trump four years ago.
They wanted a leader who would give them a voice, no matter that he never goes to church himself.
Accepting the Republican nomination on August 28, Mr Trump spoke – seemingly – directly to those same evangelicals.
“This election will decide whether we will defend the American way of life, or whether we allow a radical movement to completely dismantle and destroy it,” he said.
Joining hands in the prayer circle with the powerful evangelicals in exchange for votes is not a new tactic. In 1979 there was the Moral Majority, an organisation to mobilise the Christian right for the Republican Party.
Former president and Hollywood star Ronald Reagan also appealed to the Christian vote in the 1980s.
"After giving him the presidency, conservative Protestants shaped Reagan's policies," the highly influential Christianity Today wrote in a glowing eulogy shortly after he died. "In turn, Reagan's presidency shaped American evangelicalism."
These movements brought back the “Christian values” that many religious communities felt the civil rights movement, the women’s liberation movement, Vietnam War protests and the rise of gay rights had destabilised.
But Reagan had a tidier private life than Mr Trump. We have lost count of how many women Mr Trump paid to keep quiet. His tweets are vulgar and offensive, even for some of his fan base.
Last month, polls showed that the evangelical Trump vote was slipping.
One explanation is Joe Biden’s faith – he is only the second Catholic since John F Kennedy to win the nomination of a major party. He is also, in many ways, a centrist, traditional Democrat that could appeal across the divide.
But Mr Biden, although Catholic, has shifted his abortion stance and is now pro-choice.
His running mate Kamala Harris has pushed to repeal the Hyde Amendment, which blocks federal funding for abortion services unless the woman’s continued pregnancy will put her life in danger, or the baby is the product of rape or incest.
On the other hand, Mr Trump has also listened to his evangelical backers and delivered, from transgender policies to recognising Jerusalem as Israel’s capital. Quoting from bestselling Catholic authors has also helped.
He also pleases Christian masses by limiting Muslim refugees from coming to “his” country and wants to build a wall to turn America into a fortress. He speaks to the heart of the forgotten, white, Christian Americans who are getting “pushed aside” by Black Lives Matter and “nasty” women.
At least, that is how he sees it.
Mr Trump has the support of leading Christian figures and ministers such as Jerry Falwell Jr, whose father founded the Moral Majority in 1979, Eric Metaxas and Franklin Graham. Mr Falwell went as far as to call Mr Trump a “street fighter” for Christians.
But in August, Mr Falwell Jr resigned from Liberty University, a private evangelical institution founded by his father, after a series of personal scandals which he has denied.
Mr Falwell Jr has a close friendship to Mr Trump, but it is not clear if the sordid scandal will, by proximity to the president, turn evangelical voters away.
As one evangelical minister said in 2016 that “God’s hand intervened” to elect Mr Trump, the question today is will God’s hand do it a second time?
And in recent months, there are small but important voices within the evangelical community speaking up against Mr Trump.
"His Twitter feed … with its habitual string of mischaracterisations, lies and slanders – is a near-perfect example of a human being who is morally lost and confused," Mark Galli, a minister author and former editor of Christianity Today, wrote in his former magazine in December 2019. "It's time to call a spade a spade, to say …we are playing with a stacked deck of gross immorality and ethical incompetence."
Many Christian leaders came out against Mr Galli’s letter, but it may still have had a dampening effect on Mr Trump’s religious appeal.
There are some who are beginning to quietly look away from Mr Trump, the man who shamelessly turned their religion into a weapon.
Janine di Giovanni is a Senior Fellow at Yale University’s Jackson Institute for Global Affairs. Her next book, The Vanishing, is about the Christian minority in the Middle East. @janinedigi