Kemp - who, as Georgia secretary of state, is also in charge of elections and voter registration - faced backlash after it was reported his office had put more than 53,000 voter applications on hold, almost 70% of which are from African-Americans, because they failed to clear the state's controversial "exact match" standard.
"I don't want to run, okay?" If elected, Abrams will be the first-ever American black female governor.
But Abrams brushed off the probe as Kemp's "desperate attempt to turn the conversation away from his failures" as Georgia's secretary of state in the lead up to the gubernatorial election on Tuesday.
More than 1.5 million of the state's nearly seven million registered voters have cast ballots already.
"I'm encouraged to see so many young voters showing up at the polls, and I'm also encouraged to see that we have a growing pool of independent voters who I think will break for democrats during this election", she said.More news: U.S. grants Iran sanctions waivers to eight countries including India
The rally was the first of two the media magnate is holding for Abrams on Thursday in one of the nation's most closely watched gubernatorial races. But she also said the election is about issues like expanding Medicaid insurance and focusing state spending on public education, job training and small business startups. "I'm not testing the waters", Winfrey said. "I absolutely am voting for her", Denise replied. Democrat Stacey Abrams and Republican Brian Kemp both condemned the message, which claims to have been paid for by the 'Road to Power'.
As a black woman, Winfrey noted her kinship to two groups historically denied ballot access in the United States.
Abrams is looking to maximize turnout among nonwhites, liberal urban whites and just enough whites everywhere else, including a smattering of moderates and suburban Republicans who are disenchanted with Trump - a considerable overlap with the fan base that propelled Winfrey to her billionaire icon status.
Investigative journalism website WhoWhatWhy reported Sunday that they had received an email and document, sent from the Democratic Party of Georgia to election security experts, that highlights "massive" vulnerabilities within the state's online voter registration system.