Andrew's answer is almost exactly my own, federalism. Let each state and the majority in those states decide how they shall live. With fifty different options, there is bound to be somewhere that will meet your needs. Immediate question: "What about those in the minority who will have their lives disrupted?" I have yet to come up with a diplomatic answer for that. The core of the answer is that each individual or family will have to decide if the right they are being denied to them in one state is worth the disruption of going to another state. The Declaration of Independence says that we have the right to pursue happiness. Nowhere does it say that the pursuit would keep you where you were. This idea cuts both ways, if California's permissiveness is too much for you, you can take your family to where the neighbors will be more to your liking. Head on down South, I'm sure that there will be a gay couple down there looking to sell.
America can handle divisions. As Andrew said:
Forcing California and Mississippi into one model is a recipe for disaster.