In early 2012, the U.S. Supreme Court recognized, for the first time ever, a “ministerial exception” to employment discrimination laws, saying that churches and other religious groups must be free to choose and dismiss their leaders without government interference. In his written opinion, Chief Justice Roberts wrote, “The Establishment Clause [of the First Amendment to the U.S. Constitution] prevents the government from appointing ministers, and the Free Exercise Clause prevents it from interfering with the freedom of religious groups to select their own.” The wrench in the works here concerns the matter of delimiting the exception, given the inflation in what constitutes “ministerial” in terms of tasks.
The full essay is at "The Ministerial Exception."