But Mr. Gingrich represents a new kind of Catholic, one very different from the Kennedys, who were Democrats, political liberals and cradle Catholics shaped by the Irish immigrant church. To a Kennedy-era Catholic, divorce was a sin, labor unions were a virtue and anti-Catholic bigotry was a staple in many Protestant circles.

Mr. Gingrich is a culture wars Catholic for whom the church seems a logical home for conservative Republicans. Generations removed from the Kennedy years when Catholics predictably voted Democratic, this is a new era in which conservative Catholics and evangelical Protestants have joined forces in what they see as a defining struggle against abortion, same-sex marriage and secularism.