Gerald Greene, a white Republican from Georgia, has represented the heavily rural, majority-black District 151 in the state House of Representatives for the past three decades. Because, according to Democrats, 151 is the state’s only minority-dominated district represented by a Republican, the Democratic Party had been eyeing it as a promising pick-up for the next election—a win, Democratic leaders say, that would signify a significant correction to years of the county’s black Democrats lacking legislative representation. In early March, the party finalized the candidacy of James Williams, a retired police officer from Albany, to run what Democratic strategists believed could be a winning challenge to Greene.

Yet on March 26, Williams went from campaigning against Greene to struggling to preserve his right to run in the election at all. That day, Williams says he received a call from the office of Brian Kemp, Georgia’s Republican Secretary of State, informing him that Greene had challenged his residency—and thus his eligibility to run in the district. Greene’s petition against Williams’s candidacy had found a receptive audience among the state’s top Republicans, who decided that, on closer inspection, Williams did not in fact reside in District 151. Suddenly, the majority-black district appeared to have no Democratic candidate residing within its lines, and the Williams campaign against Greene entered a realm of deep uncertainty.

“It was astonishing that I was being challenged after having voted in District 151 for approximately 18 years,” Williams told me. “I never thought something like this could happen in Georgia.”

This development has infuriated state Democrats, who have previously accused Kemp of deploying tactics to suppress the state’s Democratic-leaning minority vote. Democrats contend that, on March 7, using Kemp’s own residency data, the party qualified Williams to run in District 151. Yet sometime around March 18, the party alleges, the boundary lines of District 151 quietly changed in Kemp’s database, edging Williams just outside of the district. Kemp’s office on Tuesday essentially confirmed this account. An emailed statement from Georgia Secretary of State spokeswoman Candice Broce said that during redistricting, “Dougherty County elections officials incorrectly designated Mr. Williams as living in House District 151. When alerted to their error, county officials corrected their mistake.” Williams, the statement noted, apparently lives in House District 154. “Our office sent the challenge to the Office of State Administrative Hearings as we do with any challenge we receive, and a hearing is scheduled for April 13.”

Not surprisingly, Georgia Democrats see this as something other than an innocent mistake. “In a district that is majority African-American and that overwhelmingly voted for President Obama in the last two elections, any voter should be highly suspect of what has occurred,” said Georgia House Whip Carolyn Hugley in an emailed statement. “The district lines changed when a white Republican incumbent was challenged by a highly-qualified black Democratic candidate.”

