I only agree with your analysis in part. There are plenty of social conservatives who are just fine with extremely liberal fiscal policies.
You are right about that, but I'd say that breed it dying out in the United States and doesn't have much impact anymore. There once was a lot of populist left southern Democrats who were basically socially conservative (Dixiecrats), but most of those folks are gone. You still see this sort in parts of South America though - areas where the Catholic Church is strong.