As one of them "foreign" people, I'm curious as to why the issue of abortion and associated matters is such a divisive subject the USA. I can understand it being divisive in largely Catholic countries but the USA is mostly protestant. Given that one could never hope to be a Republican presidential candidate unless they're opposed to abortion, and visa versa for the Democrats, is it largely a political issue that's used to galvanise a parties support base? Or are there other more deeper sociological issues at play?
PLEASE NOTE: This is not a thread about abortion, but why it is so divisive in the USA.