Gun control advocate Lucia “Lucy” McBath won the Democratic nomination for the U.S. House in Georgia’s 6th Congressional District.

McBath beat her Democratic opponent, businessman Kevin Abel, in Tuesday’s runoff after they finished as the top contenders in the state’s May primary but neither garnered the majority of the vote. She won 53.7 percent of the vote.

McBath thanked her supporters early Wednesday morning, saying she was at a “loss for words.”

“We deserve better representation in DC, and I intend to show the good people of #GA06 what a tough, determined mother can do,” she wrote on Twitter. “On to November.”

I am at a loss for words. Thank you to my supporters, friends & family. And I want to thank my dear Jordan, my rock & inspiration. We deserve better representation in DC, and I intend to show the good people of #GA06 what a tough, determined mother can do. On to November! pic.twitter.com/OqXCbw53cu — Lucy McBath (@LucyWins2018) July 25, 2018

McBath, a national spokeswoman for gun control group Moms Demand Action, will now face a challenging race against incumbent Rep. Karen Handel (R-Ga.) in November’s general election. Handel famously beat Democrat Jon Ossoff in last year’s special election ― the most expensive U.S. House race in history, with more than $50 million spent on both bids.

McBath was spurred into activism by the 2012 death of her son, Jordan Davis, a black 17-year-old who was shot dead at a Florida gas station by a white man complaining about loud music. Initially planning to run for a state House seat, McBath decided to run for Congress after the February school shooting in Parkland, Florida, that killed 17 people, most of them teens.

“I knew that I could no longer sit on the sidelines,” McBath wrote on her campaign site, “while the politicians in the pocket of the gun manufacturing lobby decide the future of our gun laws.”

She said Wednesday that Jordan was her “rock & inspiration” through the race.

As a “Mother of the Movement” ― part of a group of women who’ve lost a child to gun violence or in police custody ― McBath advocates for “common sense gun violence prevention laws,” including background checks, raising the age for firearm purchases to 21 years old and fighting against “conceal carry” measures. The two-time breast cancer survivor is also pushing for more affordable health care and improving women’s access to health services.

This story has been updated throughout.

I’ve lobbied the State House and Senate to enact common sense gun violence prevention laws that save lives. Please follow my journey as I take my message to Washington @LucyWins2018. pic.twitter.com/btZiLRTJSj — Lucia Kay McBath (@lucymcbath) April 6, 2018