A special election for the successor to Marjorie Taylor Greene’s congressional district in Georgia on Tuesday will be a test of Donald Trump’s sway, and may provide a rare opportunity for Democrats in a deep-red pocket of the southern state.

Republican former prosecutor Clay Fuller is likely to come out of Tuesday’s jungle primary, in which the top two candidates go to a runoff regardless of party, alongside retired army general Shawn Harris, a Democrat. The two would face a run-off election on 7 April.

Fuller has Trump’s endorsement and had raised more than $1m leading into voting Tuesday, but Harris, who faced Greene two years ago, has raised more than four times as much. Even though four Republican candidates dropped out before the election, the Republican field is fractured between more than a dozen candidates, including former state senator Colton Moore, a combative agitator to the right of most Republican legislators in Georgia.

Greene, also a firebrand on the right, broke hard against Trump last year, beginning by questioning his first strike on Iran in June, then by sounding alarms during budget talks that the end of healthcare subsidies would wreck her constituent’s finances. The administration’s resistance on the Epstein files was the last straw; Trump and Greene turned on each other, leading to Greene’s resignation in January to avoid a contentious, divisive primary challenge.

Fuller, a lieutenant colonel in the air national guard, is also a former Trump White House fellow and – by current Republican standards – a mainline conservative and Trump loyalist, which paved the way for Trump’s endorsement.

Harris, a soldier turned cattle rancher, won about 135,000 votes in a losing effort in 2024, a record in Georgia’s 14th district. The Cook Political Report still rates the district as R+19, but Democrats have been over performing in Republican districts since Trump’s election.

In an interview in December, Harris told the Guardian that the field for Greene’s successor appears open to a Democrat.

“I don’t care who it is, but when we do our analysis – because Marjorie Taylor Greene was so far out there – we don’t see the Republican party, Donald Trump or the local Republican party getting somebody that’s closer to the center,” said Harris. “Because if you get somebody that’s closer to the center, then guess what? You got Shawn Harris.”

Even before war in Iran, Harris said that people in Georgia are more focused on economic issues than foreign wars, and that Congress should be working on getting the cost of groceries to fall.

“The economy is very bad,” Harris said. “People know that things cost more now. People know that. You don’t have to be told, you just know it, you can feel it across the board. Middle-class families are now struggling to pay the light bill, put food on the table, trying to figure out how they’re going to pay their rent or pay their mortgage.”