Why do you not understand the basic Federalism of our constitution?
The Fed Gov has no power over issues reserved to the states and the people by the constitution.
And our founding document declares our creator’s natural laws to be the basis of our legal system, not the British common law, which was essentially what the revolution was throwing off. Common law exists at the pleasure of the sovereign.
And there is no provision in our constitution for the SCOTUS to adjudicate the “constitutionality” of any law.
State issues are completely outside of the jurisdiction of the SCOTUS. Marriage is a pure State issue.
We’re not talking about the entire federal government here. We are talking about state laws that have US constitutional implications. SCOTUS will generally not hear appeals from state supreme courts if it decided the case on “adequate and independent” state law grounds. If any federal precedent, either Constitution, case, statute, or treaty, is applied in deciding the case, SCOTUS has discretion to hear it. Hence, why SCOTUS heard Loving v. Virginia, a marriage case, since the 14th Amendment was directly implicated.
You comment that we threw off the common law is ludicrous. The 7th Amendment still allows English cases to be used in US federal court if no US precedent exists on that discreet matter. If memory serves, that hasn’t come up since before the Civil War in any serious fashion.
While the Constitution doesn’t expressly state SCOTUS has judicial review powers, it is implied and the only practical solution. Article III states: “The judicial power shall extend to all cases, in law and equity, arising under this Constitution....” If parties before the court dispute the constitutionality of a particular law or behavior, and SCOTUS cannot adjudicate constitutionality, what are they to do? Keep them in the courtroom screaming at each other and watch? Hand the litigants pistols and swords to slaughter each other, with the survivor’s position prevailing?