In the PBS News Hour, David Blankenhorn of the Institute for American Values (and Elaine Tyler May at the University of Minnesota) comment on new US Census Data on marriage in America:

"...we are in the middle of a definable long-term shift away from the authority of the institution. The most fundamental sign of this, I think, in terms of social meaning is that, several generations ago, a majority of Americans said that, if you're having trouble in your marriage, you should stay together for the sake of the children.

And now a majority of Americans say that you shouldn't do that; that's a bad idea. So, another -- a related issue is the, really, breaking of the link between marriage and childbearing. It used to be that you would never -- you know, having a child outside of marriage was frowned on by society. You really wanted to avoid that.

Now it's perfectly acceptable among many Americans. So this shift away from the institutional authority of marriage is, I think, the profoundest consequences have to do with the living arrangements of children, but it has to do also with just a new way that we're thinking about what it means to be married."