It’s hard to resist the parallels. A political figure from Massachusetts with an "exotic" religious background goes to Texas to make a speech about religion and politics. John F. Kennedy did it in 1960, speaking to the Greater Houston Ministerial Association on his way to winning the presidency. Now, it’s Governor Mitt Romney’s turn, and everyone’s talking about his opportunity to give a "JFK speech."

Well I, for one, am hoping he doesn’t follow Kennedy’s script too closely, for our soon to be first Catholic President assured his audience that there would be a strict separation between his faith and his conduct in office. However welcome those words were to people with a reflexive mistrust of "papists," they served above all else to promote an entirely secular vision of politics, a naked public square in which the only imaginable religious intervention was a bigoted or authoritarian one.

Against this scary vision of "prelate[s]… tell[ing] the President… how to act" or "religious bod[ies] seek[ing] to impose [their] will directly or indirectly upon the general populace or the public acts of its officials," Kennedy offered his "conscience," apparently uninstructed by the church with which he said he identified, but nonetheless capable of discerning the national interest. He promised, in other words, that he would resist any religious intervention in our public life and any attempt on the part of government to provide assistance to, or indeed have a relationship with religious organizations. On his watch, there would be no ambassador to the Vatican and no "unconstitutional aid to parochial schools."

Kennedy did take an admirably strong stand on behalf of religious freedom, arguing that we should regard "an act against one church… as an act against all." But he seems to have understood the threat to religious freedom as emanating largely from the religious sector itself: "I am wholly opposed to the state being used by any group, Catholic or Protestant, to compel, prohibit, or persecute the free exercise of any other religion." In his world, there was apparently no secularist threat to free exercise. Since he couldn’t imagine a form of public religious witness that wasn’t somehow coercive, he regarded pushing religion out of the public square as a defense, not an infringement, of liberty.

If a public figure made such a speech about religion today, we might suspect that he or she was hostile to religion, that the solicitude for religious freedom was exercised largely on behalf of freedom from religion, or at least from any religion that inconveniently departed from a mainstream established by the defenders of secular orthodoxy.

So Governor Romney should emphatically not make this sort of JFK speech. It certainly wouldn’t appeal to the socially conservative voters he has been so assiduously courting, nor ought it to appeal to the "faithful Democrats" to whom the principal contestants on that side of the political spectrum have been reaching out. It would, further, not value the richly pluralistic public square that has evolved since religious groups of all stripes have followed the example of the Southern Christian Leadership Conference and attempted prophetically to speak truth to power. And, finally, it would send a message that Governor Romney’s heart lay with the stricter separationists on the Supreme Court, not with the judges his Republican predecessors appointed.

What, then, should he say?

He could take one page from JFK’s book by focusing on the oath of office that he would take. By solemnly swearing to "faithfully execute the office of the President of the United States and… to the best of my ability preserve, protect, and defend the Constitution," a president commits himself to a vision of limited government. The person who sits in the Oval Office has care for some of our worldly concerns, but not of our immortal souls. Churches and religious denominations also have something to say about the former, and he ought to welcome their contribution to the debate, but he cannot, as president, use government as an instrument of salvation. In other words, he can articulate a vision of limited government while encouraging the flourishing of a civil society in which all faiths and faithful efforts are welcome.

To this end, Governor Romney could also point out that many faith traditions regard human beings as created by God with reason, to be used as a (fallible) guide in dealing with our earthly concerns. Catholics talk about natural law, Protestants about common grace, but both mean that God gave all of us conscience for our guide. There are universal truths accessible—or, if you will, self-evident—to human beings as human beings. They are not the preserve of a particular faith tradition and to be guided by them is not to impose one’s religion on anyone else. This is a major point of contact between "church" and "state," between religion and politics, and to exclude the contributions that faith traditions can make to our understanding of our responsibilities is to evince an actual hostility to religion, an irrational animus that has no place in our political life.

Next, against some of his enthusiastic supporters, Governor Romney should argue that voters who are guided by their religious views in casting their ballot are not acting unconstitutionally by imposing a religious test for office-holding. Making that claim stretches the Constitution beyond all comprehension, suggesting, indeed, that government can be the custodian of our consciences. No proponent of limited government or "strict constructionism" could hold such a view, just as no proponent of these views could believe that he was empowered to use the power of government to promote his distinctive theological opinions.

In so doing, finally, Governor Romney could argue that he honors the role of a person’s faith in informing his or her legitimate public action. Faith gives an impetus to much that is good in our public life, calling people to love their neighbors and to care for the least among us. And faith is also humbling, leading us to recognize our own sinfulness, fallibility, and finitude. We are not God and we shouldn’t act as if we were. Like a faithful voter, a faithful president ought to recognize and resist this temptation. He ought humbly to seek the assistance of his Creator before he uses his God-given gifts on behalf of the limited ends the Constitution permits government to pursue.

In other words, Governor Romney ought to make a speech in which he acknowledges that his faith matters, but that, in the Constitutional context, it can only matter in a way that enriches our pursuit of limited worldly ends. As president, he would be called to welcome and to honor all the faiths that contribute to our public life, and to resist all those that would illegitimately coerce our consciences.

I don’t know if such a speech would advance his political fortunes, but it would surely teach those with ears to hear some important truths about the role of religious faith in a pluralistic political order presided over by a limited government. In making it, Governor Romney would do us a great public service.

Joseph M. Knippenberg is an adjunct fellow of the Ashbrook Center. He is Professor of Politics at Oglethorpe University.