>> They can only overturn it via Constitutional Amendment. Veto Power doesn’t apply <<
Yes and no.
In the first place, not all SCOTUS rulings involve the Constitution. Many are simply interpretations of statutes. The Congress certainly can overrule SCOTUS in such matters, but then veto power of POTUS can subsequently overrule the Congressional act.
In the second place, the Constitution gives Congress the power to define the jurisdiction of the Federal courts. Therefore, it’s conceivable that even on a constitutional matter, Congress could limit the jurisdiction of all Federal courts. For example, Congress could pass a law that says no Federal court, including SCOTUS, shall have any jurisdiction over any state law that defines, regulates or otherwise deals with marriage. But then, such a Congressional action would again be subject to a POTUS veto.
Well, it was a Constitutional decision so that was all I was referring to. But yeah, I gotcha. ; )