Depends on where in the country. But they mostly run the gamut on social issues (i.e. abortion, religious liberty) but are left of center on cultural issues (i.e. immigration). That's why these voters reacted worse to culturally conservative Trump than they did to socially conservative Bush 43.
Also, contrary to popular belief, evangelical conservatism tends to find its base in the suburbs and among the middle and upper middle classes.
i wonder why there's such a widespread misunderstanding on this?
Probably because of the idea that being a religious fundamentalist equals being stupid, and the idea that being stupid equals being backwoods and poor.