The GOP has been doubling down on its uneducated, religious, rural base for 40 years, it isn't going to stop now. The reasons that strategy hasn't destroyed them already are gerrymandering, and that the Senate and the Presidency both favor votes from low population density areas. As far as the popular vote is concerned I don't see how Trump isn't defeated in an unprecedented fashion. Of course, the electoral college will make everything a lot tighter in practice. Still, I wouldn't be terribly surprised if the 2020 election didn't deliver Mondale level results for the GOP.