From slavery-era and post-Reconstruction miscegenation laws to the religion-fueled popular movements to ban same-sex marriage to the recent Obergefell decision which reflects a successful conservative redirection of the queer liberation movement into simply "marriage equality" and a movement to preserve marriage as a privilege and means to regulate public welfare, the entire pathetic history of marriage in America is one long case study in the failure of democracy.

For anyone interested, I can lend my endorsement to this document as both a decent overview of anarchist perspectives on marriage equality as well as a good list of further resources on the issue.