The reference to Romney's forefathers was laden with meaning. Romney is descended from a long line of Mormons, going back to the early days of the church in the 1830s.

Romney's father, former Michigan Gov. George Romney, ran for president in 1968, but dropped out after a verbal gaffe sank his prospects. Still, Mormonism was not an issue in the senior Romney's campaign. Some historians say that in effect, the Kennedy speech a few years earlier had protected Romney from undergoing scrutiny over his faith. In addition, religion was not the major stump issue it is today. And in the 1960s, the Mormon church was much smaller than it is today.

The rapid growth of the Mormon church, with 5 million members in the US and some 13 million worldwide, is cited as a cause of concern for Evangelicals. Both faiths actively seek to convert one another's members, and some Evangelicals have expressed concern that having a Mormon president would aid in the growth of Mormon membership rolls.

Before Thursday's speech, delivered at the library of former President Bush on the campus of Texas A&M University, Romney was introduced by the former president. Mr. Bush made clear that he was not endorsing Romney's campaign, and had made his library available to other presidential candidates. The audience of 300 included Romney family, friends, and advisers, guests of the library, and guests of the former president. One notable attendee was Richard Land, head of the public policy arm of the Southern Baptist Convention and an influential evangelical leader. He has not endorsed Romney, but has been supportive of his candidacy.