Three years ago, HBO aired a documentary called “3 1/2 Minutes, Ten Bullets,” which examined the tortured aftermath of the death of Jordan Davis, a seventeen-year-old boy who was shot as he sat in an S.U.V. parked at a Florida gas station. At the start of the film, you see Lucy McBath, Davis’s mother, sitting at a table, depleted, telling how she came to name her son after the Biblical River Jordan. “I wanted to name him something that would symbolize the crossing over and a new beginning,” she says. Later, you see a more resolute McBath seated in a Senate hearing room with Sybrina Fulton—whose son Trayvon Martin was also shot to death at the age of seventeen—giving testimony about Stand Your Ground laws and their impact on her son’s death.

The two moments are as apt an encapsulation as you’ll find of the significance of McBath’s victory last week in the race for Georgia’s Sixth Congressional District, situated just north of Atlanta. McBath, a Democrat who ran on a platform of growing the economy, funding education, and addressing climate change, was inescapably wed in the public’s mind to the issue of gun reform. Her despair and her resolve are equal parts of her political identity. She narrowly defeated the Republican incumbent, Karen Handel, in a race that remained somewhat low-profile among the prognostications about which districts the Democrats might flip in the midterms. Last year, the Democrat Jon Ossoff gained national attention in his bid to win the seat, which opened after the Republican Tom Price left it for what turned out to be a short stint as the Secretary of Health and Human Services in the Trump Administration. Ossoff lost to Handel in a runoff, by less than four percentage points, with 48.1 per cent of the vote. A measure of the skepticism about McBath’s chances could be seen in the fact that, before last Tuesday, the race was being referred to in some quarters as the “Ossoff race without Ossoff.”

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McBath’s victory reflects several trends: the inroads that Democrats are making in Republican suburban districts that Trump’s tax cuts and border-fearmongering were supposed to secure, the record number of women elected to public office in the face of the mainline misogyny that is a feature of the Trump era, and the fading ability of gun-rights appeals to safeguard Republican districts. It is also worth noting that nine new African-American candidates were elected to Congress in the midterms—all of them Democrats, five of them women—and that, once all the outstanding races are called, will likely bring the ranks of the Congressional Black Caucus to a record fifty-six members. All but two of them are in the House, and the majority of those members won election in majority-minority districts. The nine incoming representatives, however, were all elected in largely white districts—a fact that may complicate the calculations of the caucus and the voting behavior of its members. McBath will be the first African-American to represent her district.

There are other, subtler dynamics at play in the Georgia Sixth results. The fight over Georgia’s gubernatorial race, between the Democrat Stacey Abrams and the Republican Brian Kemp, who, until last week, served as Georgia’s secretary of state, focussed on Kemp’s record of voter-roll purges and voter suppression. Many elections come down to turnout; in Georgia, the question was how many potential voters would be turned away. Kemp, however, was just following a playbook pioneered by Handel, who preceded him as secretary of state, serving from 2007 to 2010. Early in the 2008 Presidential campaign, when it was optimistically suggested that Barack Obama’s candidacy might put Georgia in play for the Democrats, Handel engineered a purge in which some four thousand eligible voters were flagged for removal for being “non-citizens.” (At the time, I was teaching at Spelman College, and this happened to one of my students. It took, in part, the intervention of a local CNN station to get her registered; a panel of federal judges overturned Handel’s order.) The gerrymandered redistricting in the Republican-controlled state legislature was also intended to thwart Democrats.

In a sense, the race in Georgia’s Sixth District was a small-scale version of the governor’s race. McBath’s results—she won 50.5 per cent of the vote—are particularly notable, given that black voters make up roughly a third of the electorate in the state but only thirteen per cent in the district. Ossoff ran in 2017 on a platform that was similar to McBath’s on issues such as climate change, the economy, and Medicaid. Ossoff also campaigned against subsidies that made it easier for foreign airlines to compete in the United States, recognizing that Delta Air Lines is headquartered in Atlanta, and that voters employed at the nearby Hartsfield-Jackson airport were affected by the issue. (McBath worked for Delta for thirty years.) The 2017 race became the most expensive House contest ever, costing some fifty-five million dollars. McBath’s campaign spent $1.2 million, but she improved on Ossoff’s margin by more than two points.

There are a number of ways to look at this outcome. The district, despite its history as a home of G.O.P. stalwarts—it was Newt Gingrich’s seat for twenty years—was trending toward the Democrats. In 2000, George W. Bush beat Al Gore by thirty-six points there. In 2012, Mitt Romney’s margin of victory was twenty-three points. In 2016, Donald Trump beat Hillary Clinton by just a single point. It is sixteen months further into the Trump era than when Ossoff ran, and it is entirely possible that the President has worn out the grace period that moderate voters were inclined to give him last year. But, crucially, McBath represents a movement. Her son was shot by a white man named Michael Dunn, following a dispute over playing loud music, on November 23, 2012. Trayvon Martin had been shot nine months earlier, as he walked, unarmed, through a gated community where he was staying. Both deaths occurred in Florida and became central to the debate over the so-called Stand Your Ground gun laws in that state. George Zimmerman was acquitted in Martin’s death; Dunn, in a second trial, was sentenced to life without parole. The film “3 1/2 Minutes, Ten Bullets” follows McBath and her ex-husband, Ron Davis, as they pursued justice for their son over two trials. (They requested that the prosecutors not seek the death penalty.)

When I interviewed them after a screening of the film, at the Schomburg Center, in Harlem, McBath emphasized the extent to which she had channelled her sorrow over her son’s death into action with the groups Everytown for Gun Safety and Moms Demand Action for Gun Sense in America. McBath served as the national spokesperson for both organizations and testified on the dangers of Stand Your Ground laws before the Florida, Georgia, and Nevada state legislatures. In 2016, McBath, with Sybrina Fulton and seven other women who had lost children, most of them to gun violence, appeared in support of Hillary Clinton at the Democratic National Convention, under the banner of the Mothers of the Movement. McBath’s campaign Web site carefully noted that she supports “2nd Amendment rights of Georgians,” but she also promised to “push for implementing background checks for all firearm purchases; raising the minimum age to purchase a gun to 21 years of age; working to defeat conceal carry reciprocity measures; and introducing legislation to keep guns out of the hands of domestic abusers and other criminals.”

McBath was elected nine months after seventeen people were shot to death at the Marjory Stoneman Douglas High School, in Parkland, Florida, and a little more than a week after eleven people were killed in the Tree of Life synagogue, in Pittsburgh, and two were murdered in a Kentucky supermarket. She was also elected almost exactly six years after her own son died. The plague of gun violence and the intransigence of the gun lobby in the face of it have often seemed like an unbreakable stalemate. McBath’s election is a small, sure sign of hope.