Only Congress and the states can change or amend the Constitution case laws cannot trump or amend the Constitution.
Incorrect.
The Supreme Court determines what the Constitution means by virtue of its interpretive authority per the doctrine of judicial review.
The Constitution exists only in the context of its case law. And the Supreme Court would be authorized to interpret any amendment to the Constitution.
In the case of same-sex couples, that would be the 14th AmendmentÂ’s requirement that all persons have equal protection of the law. To deny a class of persons equal access to the law, the state must demonstrate a compelling interest, provide objective, documented, certified, verified evidence in support of that interest, and the motive to deny equal access must be free of animus.
Both liberals and conservatives have started threads challenging those opposed to equal protection rights for same-sex couples to provide objective, documented, certified, verified evidence in support of that opposition.
Those opposed to equal protection rights for same-sex couples have failed to do so, and any such measure denying same-sex couples access to marriage law would be struck down by the Court accordingly.