Federal constitutional amendments can't be found unconstitutional. No court has jurisdiction. Over state constitutional provisions that conflict with the federal constitution, yes. Not over the federal constitution.
The Congress can pass and the state legislatures can ratify whatever amendments to the federal constitution they want, and there's nothing anyone can do about it except the Congress passing and the state legislatures ratifying new amendments repealing the old ones. That's why there was no successful legal challenge to the 18th Amendment / Volstead Act and it required a new amendment to repeal prohibition.
The author has apparently lost sight of the fact that an amendment that was widely viewed as racially biased in intent would never be ratified. But of course it's the Puffington Host so the capacity - and power - of American white racism has no limit in the purported context.
