The top election official in Georgia, a Republican, said Donald Trump unequivocally lost the state in 2020, a day before a rally on Saturday night at which Trump repeated baseless accusations of voter fraud.

On the eve of the rally in Perry, Brad Raffensperger told the Washington Examiner: “He’s going to come, and he’s going to say what he’s going to say, but he knows in his heart that he lost.”

Last January, the Georgia secretary of state resisted pressure from Trump to “find 11,780 votes” and thereby overturn Joe Biden’s win in the state.

The phone call in which Trump made that demand is at the heart of an investigation in Fulton county.

On Friday, a Brookings Institution report said Trump faces “substantial risk of possible state charges predicated on multiple crimes”.

Regardless, the former president traveled to Georgia on Saturday for a rally in part to support Herschel Walker, a controversial former NFL running back running to challenge the Democratic senator Raphael Warnock in midterm elections next year.

Warnock and another Democrat, Jonathan Ossoff, won Georgia’s two Senate seats in runoffs in January. Observers on both sides of the aisle said Trump’s claims of electoral fraud depressed Republican turnout.

Final results in the runoffs were confirmed on 6 January, the day Trump supporters he told to “fight like hell” stormed the US Capitol in an attempt to overturn his defeat.

Raffensperger has since received death threats and attracted a Trump-backed challenger. He also presided over a new state voting law widely seen as aimed at depressing turnout in communities likely to vote Democratic.

Nonetheless, he remains ranged against Trump’s lie that Biden won the presidency illegally.

“He’s continued to promote the big lie,” Raffensperger told the Examiner, “and then he’s also fundraising off this issue, just like Stacey Abrams has.”

Abrams is a Democratic former state representative who ran for governor against the Republican Brian Kemp in 2018, losing a closely contested race and protesting that Kemp, then secretary of state, oversaw voter suppression.

She has since campaigned for voting rights and voter registration, efforts widely credited with helping to elect Ossoff, Warnock and Biden.

“Every time we’ve looked into all of these concerns, it’s clear that Donald Trump lost the election fair and square,” Raffensperger said.

“What bothers me, and it really should bother everyone, after 10 months since the last ballots were counted, we’re still dealing with this misinformation and disinformation surrounding the elections.”

Trump is happy to stoke such misinformation and disinformation, this week gaining new election audits in Texas even as a partisan audit in Arizona ended with no proof of fraud and more votes for Biden.

On Friday, Trump released numerous statements about events in Arizona. In one, perhaps tellingly, he called Republicans’ efforts there a “fraudit”.

In a letter released last week, the former president claimed to have found 43,000 “invalid” ballots in Georgia and told Raffensperger and Kemp to “start the process of decertifying the election, or whatever the correct legal remedy is, and announce the true winner”.

Happy to sling mud inside his party, Trump also attacked Kemp as “almost like a Democrat in disguise” and “a disaster” and predicted: “He’s not going to be able to win the general election anyway, because the base isn’t going to show up for him.”

In a radio interview, Trump also said Walker had jumped into the Senate race “at my behest”.

On Friday, perhaps speaking for establishment Republicans across the US, Raffensperger seemed resigned to what was coming at the rally in Perry.

“We are not going to win that bullhorn argument,” he said.

In the event, Trump delivered a predictable performance, focused on the last election and startlingly erratic during close to two hours on stage.

“The rally was as much anti-Kemp as it was pro-Trump,” the Atlanta Journal-Constitution reported. “At one point, Trump said Stacey Abrams would be a better governor than Kemp.”