They did, but they changed their minds… or they had their minds changed.
While the three leading candidates (Reagan, Anderson and Carter) were religious Christians, Carter had the most support of evangelical Christians according to a Gallup poll. However, in the end, Jerry Falwell’s Moral Majority lobbying group is credited with giving Reagan two-thirds of the white evangelical vote. According to Carter: “that autumn [1980] a group headed by Jerry Falwell purchased $10 million in commercials on southern radio and TV to brand me as a traitor to the South and no longer a Christian.”
They did, but they changed their minds… or they had their minds changed.
https://en.wikipedia.org/wiki/1980_United_States_presidential_election#Campaign
Jfc I am ashamed of my species