When I switch from 'atheist' to 'Protestant' but leave the settings as 'non-born-again' and 'not a regular church goer' it shifts me down to around 50-50.
On the other hand, I can leave it set to 'atheist' and switch it to 'born again' and suddenly 70% chance of voting Republican. I wonder if there are folks out there whose belief systems are incoherent enough that they don't believe in God but DO believe they've been born again in the evangelical Christian sense.