The socially conservative position advocates limiting behavior on the basis of morality. The challenge with this position is that the society must have a common standard of morality. In American history this was not traditionally a problem. However, with the emergence of postmodernism, it has become unacceptable to appear to the Bible or any other single standard of morality. Thus even many social conservatives have difficulty defending their position to a social liberal because their is not a commonly-held moral standard on many issues.
The socially liberal position says that laws are about defending people's rights from being violated by others. For instance, murder is illegal not (just) because it is wrong, but because it deprives someone of a right to life. This seems to work for many societies, but as with all utilitarian viewpoints it is limited in certain areas. Abortion is a challenging issue because it puts the right of the mother at odds with the rights of a (future?) baby. Whose rights supercede someonone else's? Which rights are more important? Is my pursuit of happiness more important than your right to have dental insurance?
These are considerations we must evaluate before siding on one position or another.
This is the second post in a series on the law. The first post defined common positions.