Voters line up on Oct. 20 in Sandy Springs, Ga. Early voting in the state runs through Nov. 4. (John Bazemore/AP)

A growing conflict over voting rights and ballot access is playing out in Georgia, where civil rights activists are trading accusations with Republican elected officials and where the stakes have risen considerably with the state’s new status as a closely watched battleground.

Activists said this month that as many as 100,000 Georgia ­voter-registration applications have not been processed. One of the state’s largest counties offered only one early-voting site, prompting hours-long waits for many people at the polls last week. And the state’s top election official has refused to extend ­voter-registration deadlines in counties hardest hit by Hurricane Matthew.

These developments have prompted harsh criticism from voting rights activists. Last week, the American Civil Liberties Union filed a lawsuit to extend registration for six counties affected by the hurricane. Republican Secretary of State Brian Kemp, who oversees elections, responded by taking to Twitter to rail against “left-wing activists,” whom he accused of trying to disrupt the election.

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Fresh polls in the Peach State show a tightening presidential race between Democrat Hillary Clinton and Republican Donald Trump, who has complained that the election is “rigged” against him nationwide. But voting rights advocates in Georgia say Republican state and local election officials are undermining the fairness of the vote by passing laws and adopting procedures that deter minorities and young people, groups that typically vote Democratic.

As the presidential race tightens, Democrats are going after voters in the Republican stronghold of Georgia. In Gwinnett County, a rising number of minorities could be changing the political landscape. (Alice Li/The Washington Post)

The clashes in Georgia echo battles in recent months, some still ongoing, in other states across the country, including North Carolina, Michigan, Wisconsin and Ohio.

“Georgia is ground zero, if you will, when it comes to voter suppression and voting discrimination that we’re seeing this election season,” said Kristen Clarke, president and executive director of the Lawyers’ Committee for Civil Rights Under Law.

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During the past several months, advocates in Georgia have challenged laws and procedures enacted by Kemp that they said would make it harder for people to register to vote and would unnecessarily kick people off the voting rolls. In one county, advocates say they stopped an effort by local officials to move a polling precinct that served predominantly black voters from a gymnasium to the sheriff’s office.

The New Georgia Project and other progressive groups submitted about 250,000 new voter-registration applications by the state’s Oct. 11 deadline. But they learned last week that about half of those would-be voters had not been added to the rolls, based on data from Catalist, a Washington firm that collects and analyzes voter data for progressive organizations.

Nse Ufot, executive director of the New Georgia Project, said the backlog happened partly because questionable procedures delayed the processing of applications and partly because the system was overwhelmed by the number of new applications. She said the group has launched an effort to contact more than 100,000 applicants and help them make sure they can vote by Nov. 8.

Early voting began in Georgia last week, overwhelming the one early-voting precinct in Gwinnett County, in suburban Atlanta. News outlets reported that some people waited up to three hours to vote. On Thursday, officials said they would add more machines to the single site and open two more sites Monday, five days earlier than originally planned.

Kemp said on Twitter that as of Monday morning, 578,539 ballots had been cast early in the state.

His spokeswoman declined to provide data on the number of outstanding voter-registration applications and said it is up to individual counties to process the forms.

Kemp has used Twitter to criticize the ACLU, which had asked a court to reopen voter registration for residents of Chatham County, which includes Savannah, and five other counties that were hardest hit by Hurricane Matthew. On Wednesday, a federal judge ruled against the ACLU.

In a series of tweets, Kemp decried what he said was a “stunt by the ACLU to manipulate the system & squander state, county resources days before the election.”

“We can’t sit back and watch the radical left create chaos in our state. Stand with me and protect Georgia elections!” he wrote.

“The very act of Brian Kemp peddling these bizarre conspiracy theories about the ‘radical left’ creating ‘chaos’ is itself a dangerous assault on our country’s democratic traditions,” said DuBose Porter, chairman of the state’s Democratic Party. “Just a few days ago, Kemp dismissed Donald Trump’s assertions of a ‘rigged’ election but is now falling into the same pattern of paranoia that works to undermine confidence in the system.”

Kemp, in statements during the past year, has dismissed allegations that his office’s policies are aimed at disenfranchising voters of color. In a statement last month, he touted voters’ ability to register or update their information online using a smartphone app.

“As Georgia’s chief elections official, I want to ensure every Georgian has the opportunity to register to vote and allow their voice to be heard at the polls,” he said.

[How to vote: A state-by-state interactive guide]

Advocates describe a more frustrating experience for tens of thousands of would-be voters.

In mid-September, the Georgia State Conference of the NAACP, Asian Americans Advancing Justice and the Georgia Coalition for the People’s Agenda sued Kemp’s office over a policy that required information on voter-registration applications to exactly match data in state driver’s license or Social Security records. A simple clerical error, such as a misplaced hyphen or transposed letters or numbers, could trigger a mismatch and result in an application being rejected. Voters would have 40 days to correct the discrepancies but would not be told specifically what needed to be fixed.

The lawsuit noted that out of 34,874 people whose applications were canceled between July 2013 and July 2016, 64 percent were black, compared with 14 percent who were white.

Clarke, of the Lawyers’ Committee for Civil Rights Under Law, said the groups spent a year negotiating with Kemp’s office and thought they had an agreement to make changes to the policy. But then the secretary of state said the changes would not affect this year’s election.

Days before a hearing on an emergency injunction to block the practice, the state attorney general’s office sent a letter to the court saying the matching requirement would be put on hold and applicants rejected since October 2014 would be allowed to vote in this year’s election.

Clarke said that Georgia “is unique in that a lot of the suppression we’re seeing is at the local level, with elected officials in communities that are smaller and more rural, and are not under the microscope in the same way that state elections officials are.”

One example took place in ­Macon-Bibb County in central Georgia, where local officials this year decided to temporarily move a polling precinct with a high percentage of black voters from a community gymnasium that was undergoing renovations to the sheriff’s office.

“When we complained, we were told if people weren’t criminals, they shouldn’t have a problem voting inside of a police station,” Ufot said in a recent interview.

Unable to sway officials, Ufot said, activists went door to door and collected enough signatures from residents to block the relocation. The precinct was instead moved to a facility owned by a church.

The Peach State has been reliably red in the past five presidential elections — Bill Clinton was the last Democrat to win Georgia, in 1992. But the state could be competitive this year, with Trump holding a smaller lead over Clinton than Republican presidential candidates’ previous winning margins. The contest in Georgia is close because Trump is struggling to win over college-educated white voters. Boosting turnout among voters of color, who are more likely to vote for Democrats, could tilt the state in Clinton’s favor.

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Georgia’s population, like those in other Southern states, is rapidly becoming more diverse because of an influx of immigrants and the reverse migration of African Americans from the North to the South. African Americans make up nearly 31 percent of the state’s voting-age population, Latinos 8 percent and Asian Americans 4 percent. Those groups, along with young voters, were the base of the coalition that twice helped elect Barack Obama, and their growing numbers could signal a shift in electoral power away from white Republicans, who flocked to the GOP in response to civil rights gains of the 1960s.

Ufot said she is frustrated that the New Georgia Project has had to fight so hard for the past two years against efforts by state and county officials that made it more difficult for people to participate in the democratic process.

“We acknowledge that in some areas we’ve worked to make changes, but it’s not happening quickly enough . . . and the clock is ticking.”