COLUMBIA — Dan Johnson, the Columbia-area prosecutor under federal investigation, succumbed to a wave of public criticism and suffered a blowout defeat Tuesday in the Democratic primary to lawyer Byron Gipson. 

Gipson won 72 percent of the vote, according to unofficial results, for 5th Circuit Solicitor of Kershaw and Richland counties. Johnson captured 28 percent of the vote. 

"My reaction is — wow," said Gipson, a 20-year lawyer for the Johnson, Toal & Battiste law firm in Columbia. "The people heard us. They want change and we've got to deliver."

Johnson was unable to overcome the intense scrutiny his office has faced since the March revelation that the FBI is investigating Johnson's public spending.

He didn't return messages left by phone and email Tuesday night.

Gipson entered the solicitor's race in March and vowed to bring accountability back to the office. Without a Republican opponent, he's largely expected to win the seat in November's general election.

The Post and Courier in several reports detailed Johnson’s spending on out-of-state trips, swanky club memberships and luxury Uber rides. The newspaper also reported on the thousands that Johnson has charged taxpayers for end-of-the-year office parties that included payments to Johnson’s brother, an Arizona entertainer known as DJ Phlava.

The reporting prompted an investigation by the State Law Enforcement Division. The FBI later joined the probe.

Johnson filed for re-election while under investigation, setting off more than two months of an unusually competitive and at times contentious race for 5th Circuit Solicitor in Richland and Kershaw counties. 

The Columbia-area legal community largely abandoned Johnson and rallied behind Gipson, even helping him gain a fundraising lead over Johnson. Johnson sought to cling to the support he had developed over the years in Midlands communities. 

Johnson has mostly refused to discuss his expenses, citing the ongoing investigations. But he has said that accusations that he broke the law are unfounded. 

His office hired a third-party auditor to review his expenses, though a report couldn't be produced before the primary. Johnson said he will release the auditor’s report when completed. His office is paying for it.

Meanwhile, Gipson could face opposition in the general election from former prosecutor John Meadors.

Meadors stood outside a Columbia precinct Tuesday morning asking primary voters to sign his petition to get his name on the November ballot. Meadors, who lost in a Democratic runoff to Johnson in 2010, needs 10,000 signatures by mid-July to qualify.

One voter was reluctant to sign his petition at first. When he mentioned its was about the local solicitor's office, her eyes opened wide with recognition. "We got a big mess with that," she said before adding her name.

Meadors said he had 100 volunteers at precincts in Richland and Kershaw counties collecting signatures on Tuesday. 

He declined to talk about Johnson's problems, saying only that "my opponent is 10,000 signatures."

Andy Shain contributed.

Follow Joseph Cranney on Twitter @joey_cranney.

Joseph Cranney is a reporter based in Columbia, covering state and local government. He previously covered government and sports for newspapers in Florida and Pennsylvania.