Mitt Romney did not rise on the power of his rhetoric. At the Detroit Economic Club in February, his speech was swallowed by its stadium venue, overshadowed by a gaffe (his wife’s “couple of Cadillacs”) and weighed down by leaden language. Early in the primaries, Romney’s attempts to wax poetic on the virtues of America — often by quoting patriotic hymns — were waxen.

The decision to deliver the commencement address at Liberty University, the Lynchburg, Va., school founded by the late Jerry Falwell, did not promise much better. It is the type of venue chosen by a chain-smoking Republican campaign operative who once met an evangelical in 1984 and has felt no need to renew the acquaintance. “We need to get those born-againers,” one imagines the pitch. “Don’t they all like Falwell?” Never mind that there are dozens of respected evangelical academic settings in battleground states with less culture-war baggage.

But a good speech can make use of any setting. And Romney’s Liberty University address on Saturday was more than good. It gave evidence of creative, lively intelligence somewhere near the center of the Romney campaign machine.

The speech performed a number of moves that carry a high degree of difficulty. Its language was fresh and graceful. The students heard that their faith “demands and creates heroic souls” — a phrase that deserves remembering. Romney strategically conceded the theological tensions between Mormons and evangelicals — “people of different faiths, like yours and mine” — but described a broad overlap on matters of service and morality. His depiction of this shared moral ideal was ethically rich: “justice for the persecuted, compassion for the needy and the sick, or mercy for the child waiting to be born.”

Romney managed to praise Rick Santorum while demonstrating an appealing alternative to Santorum’s tone. Romney emphasized that “men and women of every faith, and good people with none at all, sincerely strive to do right and lead a purpose-driven life” — this last phrase an homage to the title of pastor Rick Warren’s best-seller. There were deft references to evangelical heroes — William Wilberforce, Dietrich Bonhoeffer, C.S. Lewis, Charles Colson — throughout the speech.

But the most interesting element of the Liberty address was its main argument. Romney claimed that culture is the key to civilizational success — and that American culture is shaped by Jewish and Christian values such as the priority of the individual, personal responsibility and the dignity of work. These values, in turn, are strengthened in religious institutions and traditional families. Agree or disagree, Romney set out a sophisticated case for cultural conservatism: that liberal public institutions depend on virtues and values shaped in conservative social institutions.

Contrast this to the way President Obama has often approached social issues. He justified his recent switch on gay marriage, in part, as the direct application of Christian teaching. “When we think about our faith,” he said, “the thing at root that we think about is, not only Christ sacrificing himself on our behalf, but it’s also the Golden Rule, you know, treat others the way you would want to be treated.” In 2008, he justified his support for civil unions by saying: “If people find that controversial, then I would just refer them to the Sermon on the Mount, which I think is, in my mind, for my faith, more central than an obscure passage in Romans.” During this year’s National Prayer Breakfast, Obama justified raising taxes on the rich by contending it “coincides with Jesus’s teaching that ‘for unto whom much is given, much shall be required.’ ”

Agree or disagree with the policies Obama recommends, his arguments can’t be called sophisticated. They are the liberal political application of a “What Would Jesus Do?” wristband. In a mirror reflection of the religious right, Obama has a tendency to engage in partisan proof texting — which is divisive in service to any ideology. Saying “I would just refer them to the Sermon on the Mount” is a claim of divine authority that short-circuits democratic debate. Even when Obama changes his political views, Jesus somehow comes around to agreeing with him.

Injecting religion into politics is always a tricky business. Religiously informed moral beliefs about human rights and dignity have public consequences — properly debated on issues from abortion to gay rights. But the use of faith and scripture as partisan trump cards is bad for religion and for politics. On recent evidence, it is Romney who is more sensitive to the danger.