Marci Hamilton is a legal scholar specializing in questions of constitutional law who is primarily known for her expertise in the field of the separation of church and state. She received her law degree from the University of Pennsylvania in 1988 and has taught at Cardozo Law School since 1990. As part of her legal training, Marci Hamilton was a legal court for Supreme Court justice Sandra Day O'Connor. The issues which Marci Hamilton has frequently commented on include sex abuse in the Catholic Church and in the Boy Scouts of America.
Marci Hamilton is also a regular filer of amicus curiae briefs in various trials concerning her expertise on this type of constitutional law. One of her best known cases occurred in 1997, when she served as lead counsel for the city of Boerne, Texas in the case of Boerne v. Flores. The case began when Patrick Flores, then the Catholic Archbishop of San Antonio, sought to expand the premises of St. Peter's Church in Boerne. Built in 1923, the church had seats to accommodate approximately 230 parishioners. With the growth of the congregation, the church found it was routinely unable to accommodate 40 to 60 parishioners during services.
When Archbishop Flores applied for a permit to expand the premises of the church to accommodate more parishioners, he was denied on the grounds that the church was part of a historic district. In response, Bishop Flores filed suit with the district court handling cases in the Western District of Texas. In his lawsuit, Bishop Flores argued that the 1993 Religious Freedom Restoration Act (RFRA) passed by Congress protected his proposed expansion. This act was designed to provide a standard for legislation that could potentially hinder free expression of religion. Bishop Flores argued that the state of Texas was unable to demonstrate a compelling reason or interest that would justify restricting expansion of the church.
The District Court ruled in favor of the city of Boerne. As the basis for its decision, the court said that RFRA was unconstitutional. Flores then appealed to the Fifth Circuit Court of Appeals, which reversed the lower court's ruling. The city then appealed to the Supreme Court, and Marci Hamilton was brought in to argue the city's case. Her argument was successful, and the Supreme Court ruled in favor of the city of Boerne. In its majority opinion, the Supreme Court noted that RFRA, as passed by Congress, was an unconstitutional attempt to define the limits of the Fourteenth Amendment, a power reserved solely for the Supreme Court.
In addition to her high-profile work on this case, Marci Hamilton has been noted for her frequent arguments that the state of Utah is derelict in not prosecuting those who contract polygamous marriages. Specifically, Marci Hamilton has argued that though polygamous marriages do not always lead to instances of child abuse, there is a strong enough correlation between the two to justify vigorous prosecution.