President Donald Trump speaks during a campaign rally for Senate Republican candidates, Sen. Kelly Loeffler, R-Ga., and Sen. David Perdue, R-Ga., at Valdosta Regional Airport, Saturday, Dec. 5, 2020, in Valdosta, Ga. (AP Photo/Evan Vucci)

President Donald Trump speaks during an "Operation Warp Speed Vaccine Summit" on the White House complex, Tuesday, Dec. 8, 2020, in Washington. (AP Photo/Evan Vucci)

President Donald Trump speaks during an "Operation Warp Speed Vaccine Summit" on the White House complex, Tuesday, Dec. 8, 2020, in Washington. (AP Photo/Evan Vucci)

FILE - In this Oct. 10, 2020, file photo, President Donald Trump speaks from the Blue Room Balcony of the White House to a crowd of supporters in Washington. (AP Photo/Alex Brandon, File)

President Donald Trump walks off stage after a campaign rally for Senate Republican candidates, Sen. Kelly Loeffler, R-Ga., and Sen. David Perdue, R-Ga.,at Valdosta Regional Airport, Saturday, Dec. 5, 2020, in Valdosta, Ga. (AP Photo/Evan Vucci)