SCOTUS has reversed itself in the past and can do so again when it's clear that it's worked itself into an untenable position.
not after forty years, they won't. No way.
You will see that you are wrong... forty years from now.
Abortion, despite howls of protest, for example will NEVER be outlawed. They will always be legal under some definition of the life or limb of the mother. ALWAYS.
Abortion may become more restricted or less, but the stare decisis principle guarantees that established case law will NOT be overturned, ESPECIALLY after so many dedades of being established in so many jurisdictions and that goes beyond just a federal level.
and that is why the federal government cannot successfully define marriage... and it never will.
period.