At midnight, Augusta businessman Rick Allen was leading Evans lawyer Wright McLeod by about 500 votes, but neither was conceding the second-place finish that would place one of them in the runoff. The Associated Press didn't call the runner-up results because of the closeness of the race.
The margin is close enough to guarantee McLeod a recount if it holds in the official count, The Associated Press said.
Allen said Anderson has voted for significant tax increases as a legislator.
“He’s a career politician,” Allen said. “There’s no way we want to do the same thing over again.”
With final vote totals still not in, McLeod said that regardless of the primary result, “our overriding goal is to beat John Barrow.”
Anderson maintained a lead over his three opponents through the night but needed more than 50 percent of the votes to avoid a runoff.
Dublin lawyer Maria Sheffield conceded the race around 10 p.m.
“Tonight it was not in God's providence that our campaign move forward in this process,” Sheffield said. Campaign manager Kathryn Ballou said Sheffield would be endorsing one of the runoff candidates soon.
“On a personal level, I certainly appreciate the support that I've had from Augusta,” Sheffield said. “From a philosophical standpoint, I stand firm in my belief that the days of John Barrow are numbered, and we're going to elect a conservative."
Anderson said he was “prepared for a runoff. We can't relax. We can't relax until John Barrow is defeated and we can balance that budget and get back to basics.”
Anderson carried most of the rural parts of the 12th, which was redrawn by the Republican-controlled Georgia Legislature in an effort to unseat Barrow.
He won Appling, Bulloch, Coffee, Emanuel, Evans, Jenkins, Montgomery, Tattnall and Toombs counties, along with his home county, Columbia. Anderson won 5,672 votes in Columbia County, where Allen got 4,317 and McLeod had 5,238.
The runoff winner will face Barrow, D-Augusta, in November’s election.