Donald Trump’s continuing effort to bend national Republican candidates to his will and the party to do his bidding faces a test in the key state of Georgia on Saturday as the former president holds a score-settling rally there in support of candidates who could boost any future re-election agenda.

Trump’s presence in the state comes 18 months after he pressured Georgia’s secretary of state, Brad Raffensperger, to “find” enough votes to overturn Joe Biden’s victory, a conversation that is now the subject of a grand jury investigation in Atlanta.

The loss, which made Trump the first Republican presidential candidate to lose the state in 28 years, continues to rankle the former president, and he has endorsed the state congressman Jody Hice in his challenge to Raffensperger. He also backed other candidates in the state against establishment Republicans, including David Perdue against the sitting governor, Brian Kemp.

It follows a similar pattern in other states where Trump has held or plans to hold rallies as a way of showing support for Republican candidates who have offered him their fealty.

Saturday’s rally in Commerce, 70 miles north-east of Atlanta and one of the most conservative parts of the state, is expected to feature Herschel Walker, a former football player running for the US Senate; Perdue; and the congressional candidate Vernon Jones, a former Democratic state representative who began calling himself the “Black Donald Trump” after switching parties.

But Trump is playing a high-stakes game and his candidates’ success in Georgia’s May primaries is far from guaranteed.

Walker is slightly ahead of the Democratic senator Raphael Warnock in RealClearPolitics polling averages, but Jones, who dropped a bid for the governorship in February, faces a crowded Republican field for the conservative 10th congressional district, which covers part of east Georgia.

Trump’s pick for governor, Perdue, faces an even more complex struggle. He has struggled to raise campaign money and trails incumbent Brian Kemp by 11 points, according to a Fox News poll.

Perdue has toed Trump’s false line of a “stolen” 2020 election and begun claiming that his defeat to the Democratic senator Jon Ossoff, to whom he conceded in January, was also problematic. “Most people in Georgia know that something untoward happened in November 2020,” he told the talk radio host Bryan Pritchard. “I’ll just say it, Bryan. In my election and the president’s election, they were stolen. The evidence is compelling now.”

The Perdue-Kemp contest represents a personal grudge for Trump, which flared after Kemp after refused to support his bid overturn Georgia’s 2020 election result.

Trump has also sought to undermine the governor by backing Patrick Witt, who supported Trump’s election challenge, against John King, who is Georgia’s first Latino statewide constitutional officer and a Kemp loyalist. Witt is running against King in the Republican primary for state insurance commissioner.

But the larger question is how far Trump’s influence extends in shaping Georgia’s Republican politics. To some, the former president’s endorsement power is diminishing in the state.

“He will not be a help to Trump-endorsed candidates when he comes on Saturday,” the conservative commentator Martha Zoller told the Atlanta Journal-Constitution this week. “He will be negative and backward looking – and that’s not what voters want.”

Some Republican pollsters said that while Trump’s endorsement was coveted, he had diluted his influence by reaching far down the ballot or supporting late-entry candidates with little public recognition or campaign apparatus.