Detectable in Tim Kaine’s Democratic Convention speech, and in the atmosphere last night, was the beginning of a turn toward reclaiming ground abandoned by Donald Trump’s G.O.P. PHOTOGRAPH BY PHILIP MONTGOMERY FOR THE NEW YORKER

Donald Trump does not much talk about his faith, in God or anyone else, and so, as if obeying a pendular logic, the Democratic Party has begun to display its own. “When was last Dem Convention that showed video of a prayer circle and an amen?” one reporter wondered on Twitter on Tuesday night. There was more to come. A video showed President Obama singing “Amazing Grace” in his eulogy in Charleston, and the delegates held up their arms, like they were in church. As Lenny Kravitz performed, a swaying church choir occupied the stage behind him. Most meaningful, the Party last night nominated for Vice-President the Jesuit-inspired Virginia senator Tim Kaine.

Kaine’s faith, he said in his speech accepting the nomination, is “my north star for orienting my life.” He explained that he went to a Jesuit high school, with the motto “men for others,” and that this led him to volunteer with missionaries in Honduras, and then to his work as a civil-rights attorney. Kaine recalled being tested, as the governor of Virginia, by the massacre at Virginia Tech, in 2007. A biographical video showed him speaking just after the shootings, with a believer's uncommon zeal, about the courage and decency of Virginians. Detectable in Kaine, and in the atmosphere last night, was the beginning of a turn, in which the bracing black-church language that Obama has sometimes used to guide our politics is amended until it fits Hillary Clinton’s Methodism, with its soft insistence on consensus.

Last night, Kaine’s sanctimony was sometimes too much to take. “We share this basic belief. It’s simple,” he said, speaking of himself and Clinton. “Do all the good you can and serve one another. Pretty simple.” Kaine has an earnest mien and a high-pitched voice (there is a touch of the old Al Franken character Stuart Smalley), and he kept overdoing a Trump impression, in which he deepened his voice and let the vowels swell into his mouth. “Let’s talk about trust,” Kaine said, more effectively, and he sketched Trump as a swindler, who asks for trust that he always betrayed. Kaine noted that his own father had run a small iron-working shop in Kansas City, and that this was the kind of small business that Trump has repeatedly ripped off. He continued, “It just seems like our nation, it is just too great to put it in the hands of a slick-talking, empty-promising, self-promoting one-man wrecking crew.”

Kaine, though, was probably not chosen as Clinton’s running mate to be a preacher. He was chosen because he can occupy the symbolic center of American life. Early in his speech, Kaine mentioned his eldest son, who was two days into a deployment with the Marines. “Semper Fi, Nat!” Kaine cried. Later, he pointed out that his father-in-law, Linwood Holton, the former Republican governor of Virginia, was in attendance. Kaine said that Holton, who worked to integrate Virginia’s public schools, is voting for "an awful lot of Democrats these days . . . because any party that would nominate Donald Trump has moved too far away from the party of Lincoln.” Rich Lowry, the editor of National Review (which, in its horror over Trump, has been working some interesting territory between irony and despair), sensed what the Democrats were up to. “American exceptionalism and greatness, shining city on hill, founding documents, etc—they’re trying to take all our stuff,” he wrote.

Kaine is a more internally complicated politician than the pious figure on display last night, as could be glimpsed in the biographical stories published just before the Convention. Kaine is personally opposed to abortion but has maintained a one-hundred-per-cent voting record from Planned Parenthood. He is personally opposed to capital punishment and as a lawyer took on long-shot death-penalty appeals, but as governor he has presided over eleven executions. “I’ve eaten the last meal, and I’ve held the guy’s hand,” Kaine has said. “Because of that, it was kind of demystified.” Kaine’s former chief counsel told the Times that the Governor had taken comfort in the fact that he did not have to sign the death warrants for execution but, rather, only decide whether to intervene. So often we describe virtue in public life as if it is a static attribute, fixed in character. For Kaine, more honestly, it has been a process.

While the Republican Party collapses, and the left causes tumult in Philadelphia, the center of the Democratic Party is going through a quieter evolution, in the transition from Obama to Clinton. In this Convention, the Party has moved to occupy much of the ground abandoned by Trump’s G.O.P., until much of the scope of our politics is under the Democratic banner. It is the party of the fieldworkers’ organizing cry “sí se puede,” voiced in Kaine’s fluent Spanish, and the party that defends the dignity of John McCain. It courts Michael Bloomberg and relies on the energy of voters who may be tempted to defect to the Green Party candidate Jill Stein. This cannot last. The territory is just too broad, and some of it will have to be abandoned.

Vice-Presidents, who arrive to campaigns late, are usually outside the inner circle when Administrations begin, but eventually they move toward the center. It is hard to picture George W. Bush’s White House without thinking of Dick Cheney’s isolated certainty, or Bill Clinton’s without remembering Al Gore’s futurism, or Obama’s without Joe Biden’s emotive partisanship. “My friend and my brother,” the President called Biden last night, full of affection. The Kaine selection hints at particular choices: an atmosphere of pious responsibility, a preference for the consensus over the loud individual. This may be an illusion, or be subsumed by other choices. But for now it is one solid piece of information Clinton has given about what kind of President she would be. Out of everyone, she picked him.