Next week the Supreme Court will be asked to decide an issue in an area in which it has said it has no jurisdiction.
For most Americans, the Supreme Court cases being heard on Tuesday and Wednesday next week are about same-sex marriage. But the cases—Hollingsworth v. Perry (the Proposition 8 case from California) and U.S. v. Windsor (the Defense of Marriage Act case)—also are a test of the nation's democratic and decentralized constitutional structure. These cases thus are not just about marriage. They are about how we reach decisions regarding matters of deep moral significance in our federal republic.
We learned from Roe v. Wade that the Supreme Court endangers its own legitimacy and exacerbates social conflict when it seeks to resolve moral-legal questions on which the country is deeply divided without a strong basis in the text of the Constitution. The court sometimes intervenes when the legislatures of the 50 states are approaching a consensus. When it jumps into a live political controversy, the justices look like they are acting like legislators.
The system today, without the Supreme Court's intervention, is working as it should. Representatives of the people are deliberating. "We the People" are thinking. So far, nine states have extended marriage to same-sex couples; many others chosen to explicitly endorse traditional marriage.