The New York Times magazine notes that if Rahm Emanuel wins election for Chicago mayor next week, as is widely expected, it will mark 
the first time in 80 years, save once, that the city hasn't been led by a Roman Catholic mayor. But Emanuel, who is Jewish, appears to have some close connections to the church:
And while Emanuel is reluctant to discuss the role of faith in his political views, he does say that during his first Congressional campaign in 2002, he came to regard the Rev. John Cusick, who heads the young-adult ministry for Chicago’s Roman Catholic Archdiocese, as “another rabbi.” On the day Emanuel was sworn in, he phoned Cusick on the way to the Capitol to give Cusick his cellphone number. “Father,” Cusick says Emanuel told him, “if you ever think I’m doing something wrong, I want you to call me.”
In other words, it will mark the first time since 1987 that the mayor hasn't been Roman Catholic.
http://americamagazine.org/blog/entry.cfm?blog_id=2&entry_id=3452