22nd Century Issue: How much cultural variation will a society stand?

Right now, American society through its governmental apparatus is trying to address the social issue of abortion--specifically, will society tolerate women's having an abortion of a fetus?

But there's a number of issues that some society or another is attempting to resolve:  a man having more than one wife (in some places where polygamy is permitted), homosexuality and the raising of children within that environment, and permitting more than one government to occupy a region within the boundaries accepted as the government ruling the same region (claims of a caliphate over lands ruled by an recognized government controlling the region as made by jihadists), and on and on it goes.

What is the prevailing practice in democracies is to enable citizens to cast the prevailing judgment of the people or in the instance of the US, to enable the Supreme Court to make its ruling based on its interpretation of legal precedent established over time.

Malcolm X recommended that certain states enforce a prevailing practice within the confines of their own state (as I interpret his writings).  This is what, essentially, some states are trying now with respect to abortion.

The point I'm making is that this problem is a recurring one and the more used practice in resolving the differences over a practice is to let the dominant culture within a multi-faceted milieu establish the rule of law.  But in the case of abortion, that doesn't work, for while society could permit the practice of abortion, the other side of the issue is claiming that abortion, what it views as an instance of genocide is condoning murder of a baby (while some culture allowing the practice claims a fetus is not a human being)!

The point I'm making that with the advent of modern science and its technology, the issue is becoming more pressing to favor cultural differences and variation permitted in law and condoned by prevailing cultural allegiance within the society.

And the paradigm I frequently allude to is Canada--where Quebec is culturally French but within the Canadian regime.

And, note, the United States government still acknowledges that the Indian tribes may practice their traditional old ways on their tribal lands--at least, to some degree.