Abortion may be a key issue for evangelical Christian voters, but Samantha Bee says that wasn't always the case.

On Monday night, the "Full Frontal" host went back in time to the late 1970s to explain how the issue was manufactured by power-hungry leaders of the religious right and then legitimized by the Republican Party.

"Last week, we took a look at the religious right, those coveted evangelical voters that conservatives spent decades pandering to only to be dumped just before November prom for a heretical billionaire bully who only says the word 'God' when he is ejaculating on a pile of money," said Bee.

"Many people think the new religious right arose as a response to the 1973 Roe v. Wade decision," she added. "But that's not true."

Bee played a clip showing Dartmouth religion professor Randall Balmer revealing how leaders of the religious right held a conference call in 1979 to discuss which issues they should politicize. One member suggested abortion.

"Wait, were they founding a movement or deciding what toppings to get on their pizza?" asked Bee. "Now they just needed to tell the rest of us that abortion was bad."

Bee then spoke to filmmaker Frank Schaeffer, the son of prominent Christian theologian Francis Schaeffer, who produced propaganda videos (such as the one below) to promote the pro-life movement.

It was to become "the single greatest regret of my life," Schaeffer said.

"Most evangelical leaders didn't want anything to do with [the issue of abortion]. They wanted to just preach Jesus," said Schaeffer. "They thought politics was dirty. They didn't want anything to do with it. We had to talk them into it."

Schaeffer said the religious right's anti-abortion agenda was legitimized with the help of Jack Kemp, who went onto become President George H. W. Bush’s housing secretary.

"(Kemp) brought in 50 senators and congressmen including Henry Hyde and Bob Dole and a bunch of other people and gave it respectability," Schaeffer said. And the rest, as they say, is history.

Check it out in the clip above.