If a candidate declared himself the harbinger of the apocalypse, you might conclude his career in politics was pretty limited. But former US President Donald Trump is promising a day of reckoning, just as the Bible predicts – and he’s doing just fine with Republican voters.

Two serious Christian conservatives – Florida governor Ron DeSantis and Trump’s former vice president Mike Pence – have also entered the Republican primary. But can they draw religious voters away from Trump?

Associate Professor David Smith of the US Studies Centre has been studying the entrails of this looming contest. He spoke to on ABC's The Religion and Ethics Report.