Formulating a list of nominees is an interesting exercise. And it makes one thing clear: same sex marriage is nowhere near the top.
Writing in National Review in the hyperbolic language that social conservatives in the gay marriage debate so often adopt, Dennis Prager declares that "nothing as radical as redefining marriage to include members of the same sex has ever been publicly supported by a president of the United States," and goes on to claim that it is "the most radical social experiment in modern history." It isn't uncommon to hear this sort of claim from gay marriage opponents, so it's worth taking on.
Same sex marriage would permit gays to participate in an existing institution that encourages those who enter it to practice sexual fidelity, give emotional support, and provide financial stability. What social experiments in American history were more radical? I got to wondering. Here's what I came up with (assisted by my Twitter followers) :
1) The American founding, which began with the revolutionary overthrow of an existing regime and ended with the implementation of an untried form of government.
2) Plantation slavery as practiced in the American South, an arrangement different even than other forms of slavery, and one that involved the forced separation of African American family units.