It was the day after Thanksgiving six years ago, and Lucia “Lucy” McBath knew her 17-year-old son, Jordan Davis, had plans to go shopping with his friends.

Then, her phone started ringing. It was Jordan’s father.

“Jordan’s been shot,” he said, McBath recounted tearfully in a 2015 Everytown for Gun Safety video. “I didn’t know what I was going to do, but I knew somebody had to know about my child.”

Jordan Davis, a black teen, had been killed at a Jacksonville, Fla., gas station by a white man who complained that he and his friends were playing music too loudly in their car. The shooter, Michael Dunn, was sentenced to life without parole for first-degree murder in 2014.

After her son’s death, McBath, a longtime Delta flight attendant, quit her job and shifted her focus to advocating for gun control, serving as a national spokeswoman for Everytown for Gun Safety and Moms Demand Action for Gun Sense in America.

She appeared on major news networks, testified before Congress, starred in documentaries and spoke at numerous rallies. At the 2016 Democratic National Convention, she took the stage along with eight other mothers whose African American children had been killed by the police or by gun violence. She stood alongside President Barack Obama in 2016 when he announced executive actions on gun restrictions.

But, it was only last year that McBath decided to run for public office.

“I was afraid,” she told Elle in June. “I kept saying, I don’t know how to be a politician. I don’t know how to be a lawmaker. I’ve never done that before.”

On Tuesday night, McBath won a tight runoff election against businessman Kevin Abel to secure the Democratic nomination in Georgia’s 6th Congressional District.

“I am at a loss for words,” McBath, 58, tweeted after the race was called. “We deserve better representation in DC, and I intend to show the good people of #GA06 what a tough, determined mother can do.”

McBath had originally hoped to win a seat in Georgia’s state House, but everything changed in February when a gunman opened fire at Marjory Stoneman Douglas High School in Parkland, Fla., and killed 17 people, some of whom were the same age as her son. It was then that she knew she needed to do more, McBath told CNN.

“It’s just not enough to have the marches and the rallies and the speeches and the remarks,” she said. “Championing for them in Washington is still championing for my child, I’m still a mother, I’m still parenting. That’s why I believe this was the time to stand up.”

Come November, McBath will face incumbent Rep. Karen Handel (R-Ga.) in the general election.

The 6th Congressional District has not elected a Democratic representative for nearly 40 years. But during last year’s special election to replace former congressman Tom Price, Democrats came close. Democratic candidate Jon Ossoff was forced into a runoff with Handel, who then won by four percentage points. The tight race led some to believe Democrats might have a chance of winning the seat.

McBath became the latest example of a political newcomer — in her case a woman of color with a compelling personal story — prevailing in a Democratic primary. Much like Alexandra Ocasio-Cortez’s stunning upset against Rep. Joseph Crowley (D-N.Y.), women across the country are running in record numbers — and winning.

McBath is also one of several female, first-time candidates who have run for office on platforms against gun violence, moved by the deaths of their own loved ones.

Five years after the Sandy Hook school shooting, volunteers with Moms Demand Action for Gun Sense in America grew frustrated calling for legislative solutions. So instead, they shifted their strategy to running for office themselves. They trained 13 candidates to run for office last year, and by December, Reuters reported, nine had won seats ranging from state legislatures to local city councils. Fourteen more planned to run for office in 2018.

“We’re watching Mothers of the Movement get elected to city councils, school boards, & Congress,” one supporter wrote on Twitter late Tuesday night. “That’s how I know meaningful gun reform can happen.”

Despite McBath’s description of herself as the “late bloomer” candidate, her campaign has garnered much support from gun control advocates, as well as Emily’s List and prominent politicians such as Sen. Kamala D. Harris (D-Calif) and Hillary Clinton. Most recently, Rep. John Lewis (D-Ga.) announced his endorsement of McBath, describing her as a “strong mother,” “proven fighter” and “dedicated Democrat.”

Critics, including her challenger, Abel, painted McBath as a single-issue candidate who is too tied to national interests. A spokeswoman for McBath’s campaign told The Washington Post that in addition to gun violence, McBath also cites health care and education as crucial platform issues. A two-time survivor of breast cancer, she has vowed to protect the Affordable Care Act. When she grew frustrated by the education system in her neighborhood, she chose to home-school Jordan. She now pledges to work toward fully funding K-12 public education.

But McBath acknowledges what drives her vision are her life experiences, namely her son.

“Jordan guides me every single day,” McBath told CNN. “Every single day.”

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