(Parishioners pray at Immaculate Conception Catholic Church in Chicago April 10, 2008. Once solidly Irish, Italian and Polish, U.S. Catholicism is turning Hispanic and even a bit Vietnamese and African -- and immigration is keeping the church from losing its "market share" in the highly competitive field of faith in America.Picture taken April 10, 2008. REUTERS/John Gress )

(Parishioners pray at Immaculate Conception Catholic Church in Chicago April 10, 2008. REUTERS/John Gress )