Winfrey also is to appear alongside Abrams at a second town hall later on Thursday in DeKalb County.
"Let's go to the polls like you've never voted before!" said Rep. Lewis. A top Abrams aide said Kemp and Trump have contributed to a poisonous atmosphere, and that Kemp has been silent on previous racially loaded attacks on Abrams.
Last week, District Judge Leigh Martin May issued a temporary restraining order blocking the state of Georgia from throwing out absentee ballots and applications in cases where a voter's signature didn't match their paperwork.
Georgia must change its procedures to make it easier for some people flagged under the state's restrictive "exact match" law to vote, a federal judge ruled on Friday, dealing a blow to Republican gubernatorial candidate and Secretary of State Brian Kemp.
Abrams would be the first black female governor in US history.More news: Saudi, Turkish prosecutors discuss Khashoggi killing
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.
"These automated calls are being sent into homes just days before President Trump arrives, reminding voters exactly who is promoting a political climate that celebrates this kind of vile, poisonous thinking", said Abrams spokeswoman Abigail Collazo.
Prominent state Republicans have called the controversy "manufactured" and said it was meant to gin up support for Democrats ahead of the election.
Kemp's campaign called the incidents "fake" and blamed Abrams.
During a stump speech for Republican Georgia gubernatorial candidate Brian Kemp on Thursday, Vice President Mike Pence said the American people don't want lawmakers backed and bankrolled by "Hollywood liberals".