In an interview on Sunday with the Rev. Al Sharpton, Vice President Kamala Harris responded to a profanity-laden insult that former President Donald J. Trump used about her tenure as vice president, saying he had “not earned the right” to hold office again.

“The American people deserve so much better,” she told Mr. Sharpton on his show, according to a transcript released by the network. She later added, “Donald Trump should never again stand behind the seal of the president of the United States. He has not earned the right. He has not earned the right. And that’s why he’s going to lose.”

Mr. Sharpton had asked her to react to “street talk from someone who wants to be president,” referring to a rally Mr. Trump held in Pennsylvania a day earlier. After he descended to new levels of vulgarity with remarks about the late golfer Arnold Palmer, Mr. Trump encouraged his audience to yell profane words to describe the Biden-Harris administration, and added his own.

And so goes this final stretch of a profoundly split-screen campaign, with just over two weeks to go until Election Day.

Ms. Harris spent much of Sunday, her 60th birthday, at churches in Georgia, as part of the campaign’s “Souls to the Polls” mobilization effort to reach Black faith communities. Mr. Trump worked the drive-through at McDonald’s, a stunt meant to call attention to his accusation that Ms. Harris had never worked at the fast-food spot, as she has described. (Her campaign and a friend said that she had.)

Ms. Harris also fielded questions from Mr. Sharpton on her popularity with Black voters, specifically Black men, asking if she thought softening support from that slice of the electorate was because of misogyny.

Harris said a lack of support “is just not panning out in reality,” pointing to what she said were about 10,000 people at her rally in Atlanta on Saturday.

“I am very clear,” she added, “I must earn the vote of everyone regardless of their race or gender.”

Ms. Harris also suggested that the question had been broached by “uninformed” reporters, leaving out that her most visible surrogate, former President Barack Obama, wondered aloud onstage if the lack of support wasn’t because some Black men “just aren’t feeling the idea of having a woman as president.”