ATLANTA — Rep. Lucy McBath is endorsing former New York City Mayor Mike Bloomberg in the Democratic presidential primary, she announced on Wednesday.

The Marietta Democrat's signature issue is gun safety, and she has been closely aligned in the past with Everytown for Gun Safety, a gun control advocacy founded and funded by Bloomberg.

McBath became involved in the issue after the loss of her own 17-year-old son in 2012 when he was shot and killed during an argument at a Florida gas station.

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“I first met Mike when I was searching for ways to fight against the dangerous gun laws that ripped my son from my life," McBath said in a release. “Mike gave grieving mothers like me a way to stand up and fight back. Nobody running for president has done more for the gun violence prevention movement than Mike. I am proud to stand with him in this race, and work with him when he is in the White House to keep our communities safe.”

The endorsement comes at a critical and contentious moment for Bloomberg, who is drawing closer scrutiny as he gains more prominence in the Democratic race.

His "stop and frisk" policy as New York City mayor has long drawn sharp criticism for disproportionately targeting people of color, and earlier this week the hashtag #BloombergIsARacist trended on Twitter.

The former mayor is beginning to gain ground in the polls, with about 14 percent support among Democrats in the RealClear Politics polling average, despite not starting his campaign until late November and not even being on the ballot in the early voting states.

The March 3 Super Tuesday votes will mark his semi-official entrance into the race. The next debate, next week in Nevada, will be the first in which he appears.

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