In 1996, in its most far-reaching affirmation of LGBT rights up to that time, the U.S. Supreme Court found that amendment to be unconstitutional. The case was Romer v. Evans.
Associate Justice Anthony Kennedy wrote the majority opinion for the 6-3 decision.
This case doesn't exactly fit in with this series on privacy, because it does not cite the cases of Griswold and Roe, that I described in earlier posts. But I include it, because Romer is cited, along with Griswold and Roe, in the Court's 2003 opinion in the case of Lawrence v. Texas, which this series is leading up to.
Apparently, because the issues in Romer involved discrimination in employment, housing, etc., the majority of the justices felt that their decision could rest firmly on the equal-protection guarantee of the 14th Amendment, rather than the case law that had derived a right to privacy from that amendment and other constitutional provisions.
In dissent, Associate Justice Antonin Scalia wrote that the Colorado vote represented
a modest attempt by seemingly tolerant Coloradans to preserve traditional sexual mores against the efforts of a politically powerful minority to revise those mores through use of the laws.
Therefore, as Scalia saw it, there was a justification for the voters' action that the Court was bound to respect.