Ms. Jones said she felt like it was kind of a big deal to plant that sign in the northern Atlanta suburbs, which were once a bastion of Southern conservatism but now appear to be in political flux, in part because of more liberal newcomers like herself.

So she and Ms. Winfrey talked about the sign, and Ms. Winfrey shot a video of it, and Ms. Winfrey asked Ms. Jones about Ms. Abrams, and Ms. Jones said she was voting for her — although she had not yet because the lines for early voting had been so long. Polls show a tight race between Ms. Abrams and Brian Kemp, the Republican nominee.

The entire encounter lasted eight to 10 minutes. Ms. Jones said it was somewhat surreal to have Oprah Winfrey (and her rather large entourage) on the lawn of her quiet suburban street. Then again, part of the Oprah mystique is that after someone does a double-take after seeing her in person, she just seems to get on with the business of being a normal human. You open the door, and there she is canvassing, clipboard in hand, and maybe you give a wild yawp of recognition and excitement.

Then again, such audiences do not come every day, and Ms. Jones made the most of it. She told Ms. Winfrey about a speech she saw her give at the Kennedy Center, and how it had brought tears to her eyes and made her think that maybe the problems of race and politics in this troubled country really can improve.

“I said, ‘I hope you run in 2020,’” Ms Jones recalls saying. “She said, ‘No, no.’”