Why are some states community property states, while others are equitable distribution states?

Theoretically, it could be, if all the states agreed to do so. This is not likely to happen, however, since divorce and family law are matters of state law, not federal law. Each state believes that circumstances, conditions, and environment are different enough to warrant each state to have a different approach.

Nine states – Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, and Wisconsin – are community property states. (You probably noticed that most are in the West.) Community property states have the philosophy that marriage is a communal undertaking; each spouse contributing equally, in his or her own way, to the success of the marriage. The spouse who earns the wages is not valued higher than the spouse who keeps the home.

In a community property state the property is divided equally between the spouses, unless they have a premarital agreement in effect that states otherwise.