“The governor’s done nothing, he’s done absolutely nothing. I’m ashamed I endorsed him," the president said of Brian Kemp.
Mr Trump made the comments during a wild interview — his first since the election — phoning in to speak on-air with Fox News presenter Maria Bartiromo.
The frustrated president spoke at length about his baseless allegations of widespread electoral fraud claiming at one point to “have thousands of votes, in some cases hundreds of thousands of votes, more than we need in every swing state”.
He accused judges and electoral officials of “making deals” and referred to “this character in Georgia” as a “disaster” — presumed to be a reference to Georgia Secretary of State Brad Raffensperger — before laying into Governor Kemp.
Last week, Mr Raffensperger, also a Republican, certified the state’s presidential election results for Joe Biden, the first time Georgia has gone for a Democrat in a presidential race since 1992.
This set off a wave of denunciation from Republicans, who insisted without substantial evidence the results must be fraudulent.
On Thanksgiving, the president referred to Mr Raffensperger as an “enemy of the people”.
Continuing to speak about Georgia on Fox News, Mr Trump undermined his own party’s get-out-the-vote strategy for the Senate runoffs in January by falsely claiming that they too would be rigged.
“Look at the election you have coming up right now. You're using the same garbage machinery, Dominion,” he said referring to his unfounded conspiracy theory regarding Dominion Voting Systems, that the company has repeatedly refuted.
"I'm ashamed that I endorsed him" -- Trump disses Brian Kemp for not doing more to help him steal the election in Georgia pic.twitter.com/pCgF7dFIk2
— Aaron Rupar (@atrupar) November 29, 2020
Any lack of faith in the process presents a huge political risk to Republicans, who could lose control of the US Senate if GOP incumbents David Perdue and Kelly Loeffler lose their run-off races.
However, the president, as well as both Georgia senators, have spent weeks attacking Georgia’s election process.
RNC Chair Ronna McDaniel was bombarded with questions from Republican voters on Saturday asking why they should make an effort in the election when the process was rigged.