Mark Joseph Stern has a very useful backgrounder at Slate on the move to stifle the black vote in Georgia.

Because of its history of racist voting laws, Randolph County was once required to seek federal permission before altering its election procedures. But after the Supreme Court gutted this oversight in 2013, the county was freed to crack down on the franchise. It is no coincidence that its election board chose this moment to shutter most of its polls: In November, the popular Democrat Stacey Abrams will compete for the governorship against Republican Brian Kemp, the current Georgia secretary of state. Kemp, who has devoted his time in office to a ruthless campaign of voter suppression, called upon Randolph County to abandon the plan when it spurred widespread outrage. That being said, the key figure in the Randolph County controversy is a Kemp ally who was handpicked by the secretary of state to close polls throughout Georgia.

Emphasis added.

To understand the brazen attack on black suffrage now occurring in Randolph County, it’s important to remember that Georgia is in the midst of a seismic demographic shift. As whites cease to be the majority in more and more counties, Republicans have clung to power by disenfranchising minority voters. Kemp’s opposition to the Randolph County plan marks the first time that he has adopted an affirmatively pro-suffrage stance. During his nearly eight years as secretary of state, Kemp engaged in mass voter purges, removing hundreds of thousands of voters from the rolls. State officials appear to have singled out black voters in targeted purges.

…

Perhaps most egregiously, Kemp launched an investigation into Abrams’ efforts to register more minority voters despite no evidence of fraud. He used the probe to harass and intimidate voting rights advocates. Later, he refused to register 40,000 would-be voters who had signed up through the drive. Speaking to Republicans behind closed doors, Kemp explained the stakes: “Registering all these minority voters that are out there … if they can do that, they can win these elections.” During Kemp’s tenure, Georgia’s population has increased substantially—yet the number of registered voters has actually gone down.

And Kemp seems to have played a big part in the Randolph County closures, even though he backed away once people noticed.

At the meeting on Thursday night, the election board revealed that the move had been encouraged by Mike Malone, an associate of Kemp’s. Malone, who attended the meeting, explained that Kemp—who now claims that the poll closures are a bad idea—had asked him to go around the state and “recommend polling place closures” to various counties. Ten Georgia counties have already taken Malone’s suggestions and closed polling places. All of those counties have large black populations.

Emphasis added again.

Kemp doesn’t need to continue shuttering polling places to disenfranchise minority voters in November. He has spent eight years purging black voters from the rolls and canceling their registrations. Last-minute chicanery may be helpful to Kemp, but it probably isn’t worth the publicity nightmare. It’s possible he’s already suppressed enough to votes to win himself four years in the governor’s mansion, a perch he’d doubtless use to continue his erosion of democracy in Georgia.

I recommend reading the whole piece; it’s shockingly informative.