A majority of American Christians support legal abortion, aside from white evangelical Protestants where support for legal abortion is 24%. Overall, 60% of Americans support it. So this doesn't really add up. I'm pretty sure Trump's sudden change in fortunes was due to James Comey suddenly announcing that Buttery Males were back on the table at the last moment. And let's not overstate how much support he actually had in the end. He won with the worst margin in history.