Hesiod at Counterspin Central has had some funny suggestions sent in. Let's try to add some more. After all, it is pretty ridiculous to write bits of petty bigotry into the basic law. Maybe underlining the silliness of it all is the best way to go.
My opening suggestion for a new amendment would be this:
GIVEN that scientific studies have conclusively proven that the lowest rate of sexually transmitted diseases, and the lowest incidence of spousal violence and child abuse, is found in monogamous lesbian relationships.
IT SHALL BE ORDERED THAT no male person in the United States shall be allowed to marry any other person whatsoever.
Congress shall have the power to enforce this regulation with appropriate laws.
Hey, who could argue?