Same-sex marriage is pretty much a settled issue by now, though of course it will probably take a few more years before all the appropriate laws are in place, and there will no doubt be a few noisy but futile rear-guard actions here and there in state legislatures. But since the under-40 group in this country is overwhelmingly in favor of allowing same-sex marriage, and since they are becoming the majority voting block in the nation, demographics will assure that it becomes the law of the land within a few years, even if the Supreme Court punts on the cases heard this week.
We have lived through the racial segregation battles, the women's rights battles, the abortion battles (not yet quite settled), and the gay/lesbian rights battles, culminating in the same-sex marriage battles. It is interesting to speculate about what will be the next big social issue we will face.
I suspect it will be a battle over assisted-suicide, the right of people faced with an incurable debilitating disease to choose legally to end their lives while they still have some acceptable quality of life, and for doctors to help them legally with this process. An aging population and the unsustainable costs of Medicare will help drive this issue. The aging population means we will have more and more people faced in their old age with incurable debilitating diseases that might decimate their finances and the emotions of their families, and which will strain the resources of hospitals and nursing homes. The Medicare issue is driven by the fact that about 40% of Medicare spending is on the last month of people's lives, providing very expensive but essentially futile medical care.
But it might be a battle over legalizing drugs, so as to take the money out of the drug business. The "war on drugs" has gone on for decades, at enormous cost, yet all it has accomplished is to nurture the growth of huge international drug cartels with finances exceeding those of small countries. Any student of history might have foreseen this, looking just at the history of alcohol prohibition in this country, where prohibition simply nurtured the growth of smuggling gangs, and did almost nothing to reduce alcohol consumption. The invariant lesson of history is that prohibiting a thing which has a strong demand just makes it very profitable to smuggle it, and if it is an addicting substance, to addict more people to it.. The only real solution is to reduce the demand. Since the production cost of drugs is miniscule (marijuana was a roadside weed before all this began), legalizing production would drop the cost dramatically and deprive the cartels of their huge profits. Indeed, the drug cartels would no doubt pour a great deal of their illegal profits into politics and public relations to try to prevent legalization, for exactly that reason.
It will be interesting to watch.