"I'm not here because I'm making some grandstand, I'm thinking about running myself", Winfrey said.
The actress is set to hit the campaign trail for Abrams this week and gave a heartfelt speech at Thursday's event.
"She's home!" Winfrey says in the video, standing at a door. Abrams and Kemp are virtually tied, according to recent polling.
Former U.S. President and Georgia Governor Jimmy Carter asked Kemp to resign his position as Georgia's secretary of state, saying his role in state government imperiled popular confidence in the election.
More than 1.5 million Georgians already have cast ballots.
"She is a phenomenal candidate and person and she can make history by becoming the first ever Black Women elected Governor in America", he wrote in an Instagram post.
The ruling by Eleanor Ross, the US district judge for the northern district of Georgia, affects more than 3,000 people whose voter registrations were put on hold over possible citizenship issues.
In her remarks at Thursday's town hall with Abrams, Winfrey told the crowd that she is a registered independent, "because I don't want any party and I don't want any kind of partisan influence telling me what decisions I get to make for myself".
Republicans in Georgia, including Kemp, have pushed for strict voter ID laws, citizenship checks and aggressive voter roll maintenance in the name of protecting elections against fraud and noncitizens voting.
"All of us may have been created equal, but if you're woke. you've got sense enough to know that everybody is not treated equally", she said.
Kemp did not address the robocalls at his only scheduled campaign stop on Saturday, at a Cuban restaurant in a north-Atlanta suburb. Kemp hails from Republicans' conservative wing and embraces President Trump. "I am here today because Stacey Abrams cares about the things that matter".
"It's like a domino effect", said Sara Henderson, executive director of Common Cause Georgia, about the voting issues in Georgia.