As Joe Biden jogged onto that outdoor platform in Wilmington, Del., on Saturday night, one sensed a cast change on the national stage of seismic proportions.

Exit Richard III. Enter Atticus Finch.

It’s not mere hype or sentimentality to propose that the victorious Biden cut a figure akin to the kind, purposeful character Harper Lee created and Aaron Sorkin reinvigorated on Broadway in “To Kill a Mockingbird.” In the conciliatory tones of his maiden speech as president-elect, Biden made a pitch to our better natures in a manner that reverberated with Finch-like magnanimity and rectitude.

“Now let’s give each other a chance,” Biden said Saturday — as if to quickly set aside the divisions Donald Trump sought to exploit over the length of his desultory tenure. “It’s time to put away the harsh rhetoric. . . . This is the time to heal in America. To marshal the forces of decency, fairness, science and hope.”

You might forgive a drama-deprived theater critic for looking to his field of coverage, shut down by covid-19, for analogies that help frame these preliminary performances of our next president and vice president, Kamala D. Harris. Her elevation, too, as the first woman of color elected to the second highest of offices, conveyed intimations of “Mockingbird,” one of the most widely read novels in America. Here, one imagines the fulfilled dreams of Calpurnia, the indomitable Black housekeeper in Atticus’s Maycomb, Ala., home, a woman of keen insight for whom opportunity was frustratingly denied. In her remarks Saturday, Harris exuberantly invoked the women who came before her, women of more accomplishment than Calpurnia but none with more of a thirst for justice.

Biden is not a great orator; it may be that his lifelong struggle with a stutter precludes that possibility. (For a harrowing reminder of how anguishing a hurdle that can be for a person in the public eye, re-watch Colin Firth’s Oscar-winning performance in “The King’s Speech.”) But his remarks over the blaring of the car horns and cheers of supporters in the Delaware parking lot pointed to more substantive values, and to a man of heart and spirit. More than a year ago, when I followed him around Iowa for a story about his performative campaigning style, I sensed a man adrift — a Willy Loman on the road, desperately trying to make a sale.

In Delaware, on home turf, fresh from an election called in his favor, he seemed stronger, more resolute, a winner nationally in his own right, a man as secure in his convictions as Atticus Finch himself.

The references to a book and play about a White lawyer who, in the Jim Crow South of 1934 defends a Black man falsely accused of rape, might strike some as dated: The story by contemporary standards displays some patronizing whiffs of White liberalism swooping in to save the day. But the parallels go beyond that trope, to other qualities that Atticus embodies, and that Biden reminds us of. Like Atticus, for instance, he is a devoted family man, widowed at an early age and compelled to raise children on his own. (Atticus, alas, doesn’t find a Dr. Jill.)

The message of tolerance Biden delivers could come straight from Atticus, who is also a politician, by the way: He’s an Alabama state legislator at the time he’s defending Tom Robinson, the laborer railroaded by a racist and a system lined up against him. It happens to be the opposite of the inflammatory rhetoric of the figure America is tossing out of office. Remember the inaugural address invoking “American carnage”? In the aftermath of such polarizing language, though, there may be a naivete — however noble — in believing common ground is achievable. Biden underlined this Saturday by reaching out to Trump supporters, insisting he will be a president “who doesn’t see red states and blue states, only sees the United States.”

That notion is also central to “Mockingbird.” During Biden’s speech, I was compelled to reflect on a debate at the heart of Sorkin’s adaptation, as Calpurnia confronts Atticus over his insistence that his children show their racist neighbors — and even Bob Ewell, the vicious sexual predator who sets Tom Robinson’s tragedy in motion — courtesy and respect.

“What is the virtue of teaching Jem and Scout that Bob Ewell should be treated with respect?” Calpurnia demands of Atticus.

“Virtue,” Atticus replies. “The virtue is that it’s virtuous.”

“I don’t know what that means,” Calpurnia says.

“It means,” Atticus tells her, “I don’t want them hating people they disagree with.”

Calpurnia’s rejoinder taunts Atticus with his own words. “ ‘You gotta give Maycomb time, Cal. This is the Deep South, you gotta give ’em time,’ ” she says. “How much time,” she adds bitterly, “would Maycomb like?”

The terrible ending for Tom Robinson in “Mockingbird” suggests Maycomb isn’t nearly ready in 1934. But Atticus, like Biden, won’t let go of his faith in what’s to come. The play comes to an end soon after Atticus enumerates for Calpurnia a short list of local people they can count on, to push for a better day.

“Smaller armies have changed the world,” Atticus says. “Joy cometh in the morning, Cal.”

Maybe, just maybe, it does.