Discuss the relationship between law and morality as it plays out in Supreme Court case(s).?

What cases clearly show this relationship between law and morality? (Cases that focus on a particular field, such as incorporation or substantive due process, would be best). The relationship between law and morality refers to the usage of morality, or a higher indivisible set of rights that can be used as a basis for judicial decisions (i.e, natural law). Would cases like the Slaughterhouse Cases count as showing a relationship between law and morality in its argument?