Washington: The descent of the 2016 presidential campaign last week into the realm of sex tapes and marital infidelity was remarkable enough in its own right, but it also offered a reminder of what has been largely absent from the race: a debate about issues of public morality that for decades have been at the heart of the country’s political divide.

In a striking departure from the recent history of White House campaigns, there has been almost no discussion of abortion or gay rights, two of the most animating issues for millions of American voters.

“This is more about this year’s candidates than it is about the country,” said Russell Moore, the public face of the Southern Baptist Convention. “I don’t think America is as secular as this campaign would have you think.”

The country may get a reminder of that Tuesday evening during the vice-presidential debate.

The two men who will face off, Senator Tim Kaine of Virginia and Governor Mike Pence of Indiana, share a deep religious faith that is central to their politics, but has been obscured by a more profane than holy race on top of the ticket.

While both men are devout, they represent different strands of Christianity in American life, a contrast that is likely to be on display as they discuss their positions on social issues and how religious beliefs would guide their approach to governing.

Pence, who was raised Catholic, turned toward evangelical Christianity when he was in college and has made no secret of how cultural issues have shaped his politics. He was one of the most outspoken foes of abortion rights and same-sex marriage when he was Congress. And as Indiana’s governor, he became engulfed in controversy after he signed legislation allowing the state’s business owners to deny services to gay, lesbian and transgender people for religious reasons.

But Pence, whose signature line is that he is “a Christian, a conservative and a Republican — in that order,” finds himself in a campaign devoid of any debate about the moral questions that have for decades been central to the country’s right-left political divide.

Kaine, who like Pence has Irish roots and was raised Catholic, had his faith forged when, during law school, he went to Honduras and served as a missionary for the Jesuits. It was there that he embraced a brand of liberation theology centred on social justice that would eventually be one of the forces propelling him into government.

Early in his political career, Kaine’s style of Catholicism made him uneasy with some elements of the Democratic Party, particularly on issues like abortion rights and same-sex marriage. While he has since shifted on those issues to accommodate his party — and his running mate — he remains unapologetic about how important his faith is to his career in public service.

“I’ve been very plain about my time in Honduras and about how important my own spiritual life is to me as my big motivator in this,” Kaine said in an interview.

He said he had not encountered any discomfort from his party, which polls show to be increasingly secular, when he talks about his religious beliefs.

“It doesn’t divide you from people,” he said. “It actually connects you to people because they’re sceptical about people in politics but curious about us, too, and if you share with them what motivates you, that gives them some understanding of who you are.”

But the openness with which the vice-presidential candidates discuss religion, and their focus on moral issues, have not been shared by their partners atop the ticket.

Donald Trump, who has been married three times and boasted of his affairs, does not discuss matters of sexual morality, even when speaking to Christian conservatives. In a break from recent Republican nominees, Trump did not mention abortion or even allude to the sanctity of life a single time in his marathon acceptance speech at this summer’s Republican National Convention.

Hillary Clinton prefers to draw attention to Trump’s statements on race and gender, painting him as an outlier from his own party rather than, in the fashion of most Democratic presidential candidates, linking him to the Republican Party’s hard-line social platform.

And some people of faith have been frustrated by the fact that the issues they have fought over for years are all but missing from the campaign. Oran Smith, who heads South Carolina’s Palmetto Family Council, said he was reminded of the old line about Christian conservatives and the Republican Party: “We’re on the bus, we’re just not driving the bus.”

He said this election demonstrated why evangelicals need to be more assertive in Republican politics, urging them to “take over the party infrastructure,” at least in early-voting Iowa and South Carolina.

For now, though, people of faith are choosing between two candidates uneasy discussing religion.