I wasn't really looking for a historical precedent for the recent spate of referendums banning gay marriage, but this caught my eye:
In the mid-19th century, the fiercely anti-Semitic völkisch movement appeared in Germany. One of the major demands of the various völkisch groups had been the disemancipation of German Jews and banning sexual relations between those considered to be of the “Semitic race” and those considered to be of the “Aryan race”. In 1881, a petition presented to the German government by the völkisch groups demanding Jewish disemancipation and the banning of marriage and sexual intercourse between “Aryans” and “Jews” had collected over a million signatures.As the Nazis tightened their grip on Germany, oppression of the Jews continued, leading to the enactment of Nurmeberg Laws. Like any sociopath, the Nazis claimed to be "saving" something. In this case, the German people were told they were being saved from all sorts of sexual corruption
The average person....is made to believe that he must choose between compulsive (legally enforced) sexual morality on the one hand and sexual anarchy on the other hand.The Nuremberg Laws started off as laws about sex. .....
-Wilhelm Reich, The Mass Psychology of Fascism
But of course in announcing the Nuremberg Laws Hitler had to claim there was a conspiracy (homosexual agenda anyone?) and that he was merely acting in self defense:
...Bitter complaints have come in from countless places citing the provocative behavior of Jews....a certain amount of [conspiratorial] planning was involved....[To prevent] vigorous defensive action by the [Aryan] people, we have no choice but to contain the problem through legislative measures..And if you read the Nuremberg Laws, it's hard not to think "Christ on a cracker, it's DOMA!
The Laws for the Protection of German Blood and German Honour
(September 15, 1935) Section 1
Marriages between Jews and citizens (German: Staatsangehörige) of German or kindred blood are forbidden. Marriages concluded in defiance of this law are void, even if, for the purpose of evading this law, they were concluded abroad.
Proceedings for annulment may be initiated only by the Public Prosecutor.
Extramarital sexual intercourse between Jews and subjects of the state of Germany or related blood is forbidden.......
The reason it took until 1935 to introduce the Nuremberg Laws was that there was disagreement about how to define "Jews" and how to identify them individually. In practice, even members of the Christian clergy were subject to be classified as Jews based on their grandparents.
But other forms of discrimination were already well underway:
In the first year of the Third Reich,1933, they had been excluded from the public office, the civil service, journalism, radio, farming, teaching, the theater, the films....Of course they were banned from teaching - would you want your child be indoctrinated by one of them?
-Willaim Shirer, The Rise and Fall Of The Third Reich