In the beginning, there was candidate John F. Kennedy, who told an assembly of Protestant ministers not to worry about his Catholicism because, "I believe in a president whose religious views are his own private affair." In that influential 1960 address, Kennedy boldly proclaimed: "I do not speak for my church on public matters, and the church does not speak for me.

"Whatever issue may come before me as president -- on birth control, divorce, censorship, gambling or any other subject -- I will make my decision in accordance ... with what my conscience tells me to be the national interest, and without regard to outside religious pressures or dictates. And no power or threat of punishment could cause me to decide otherwise."

And so it came to pass that -- politically speaking -- JFK begat the Kennedy dynasty, which begat Mario Cuomo, who begat Geraldine Ferraro, who begat Joseph Biden, who begat Rudy Giuliani, who begat John Kerry, who begat Arnold Schwarzenegger, who begat Nancy Pelosi and so forth and so on.

Looking back, it's clear that Kennedy's high-risk visit to the Greater Houston Ministerial Association changed Catholic political life. That's why one of America's most outspoken Catholic leaders recently seized an opportunity to deliver a very different message to another Protestant audience in Houston.

Kennedy's speech was "sincere, compelling, articulate -- and wrong," claimed Denver Archbishop Charles Chaput, at a Houston Baptist University forum on faith and public life. "His Houston remarks profoundly undermined the place not just of Catholics, but of all religious believers, in America's public life and political conversation. Today, half a century later, we're paying for the damage."

The key, argued the archbishop, is that Kennedy did more than endorse the separation of church and state. He did more than plead for religious tolerance in the public square, after generations of tensions between Catholics and Protestants.

Ultimately, that Kennedy did was pledge to separate his faith from his personal conscience, thus building a high wall down the center of his own heart, mind and soul. How is it possible for Christians to do this, Chaput asked, when dealing with profoundly moral issues such as health care, immigration, abortion, poverty, education, religious liberty, family life, sexual identity and matters of war and peace?

"Real Christian faith is always personal," he said, "but it's never private."

Political and religious leaders have been debating the meaning of Kennedy's words ever since he spoke them. This was especially true during the 2008 presidential race when critics dissected the beliefs of several candidates who openly discussed their religious beliefs -- such as Mitt Romney, Mike Huckabee, Sarah Palin and, of course, the future president, Barack Obama.

During a Fordham University forum on "The Kennedy Moment," political theorist William Galston of the Brookings Institution said that the key to the 1960 address was the candidate's bold insistence that his private spiritual views should not even be discussed because they "do not influence his views on public matters."

Kennedy also endorsed a "separation between democracy and God," noted Galston, former senior domestic policy adviser for President Bill Clinton. In fact, he used the word "God" only once, in a reference to the presidential oath of office.

This speech "could have been given by a nonbeliever. Indeed -- deep breath -- I rather suspect it was," said Galston. "At the very least, there is no indication that JFK regarded the church as having any rightful authority over his public conduct."

For Chaput, it's impossible to concede that the teachings of the Catholic faith should have nothing to do with the public lives, vocations and actions of individuals who continue to call themselves faithful Catholics.

Nevertheless, 50 years after Kennedy's speech in Houston "we have more Catholics in national public office than ever before. But I wonder if we've ever had fewer of them who can coherently explain how their faith informs their work or who even feel obligated to try," said the archbishop.

"At least one of the reasons for it is this: Too many Catholics confuse their personal opinions with a real Christian conscience. Too many live their faith as if it were a private idiosyncrasy, the kind that they'll never allow to become a public nuisance. And too many just don't really believe. Maybe it's different in Protestant circles. But I hope you'll forgive me if I say, 'I doubt it.' "