Should they truly be falling under the same social umbrella? What am I missing here?
The thing is that "social conservatism" is a nice, short-hand way of saying "religiousness" in modern America. Think about the big social issues: abortion, same-sex marriage, stem cell research, teaching evolution, abstinence-only sex education. Each of these is most loudly, vigorously, and reliably decried by religious individuals. So they get grouped together because the groups that are most visible are united on the issues in question.
So there's no reason why the two must be linked - there's nothing about one that implies the other, unless you're using the Bible as your source for social policy.
no subject
The thing is that "social conservatism" is a nice, short-hand way of saying "religiousness" in modern America. Think about the big social issues: abortion, same-sex marriage, stem cell research, teaching evolution, abstinence-only sex education. Each of these is most loudly, vigorously, and reliably decried by religious individuals. So they get grouped together because the groups that are most visible are united on the issues in question.
So there's no reason why the two must be linked - there's nothing about one that implies the other, unless you're using the Bible as your source for social policy.