Representative Eric Swalwell of California announced on Monday that he was ending his campaign to be the 2020 Democratic nominee for president, becoming the first candidate to do so. Swalwell made gun violence prevention policies the crux of his candidacy, but failed to separate himself from a crowded Democratic field that largely shared his views on the need for stronger gun laws.

Swalwell said he was inspired to run by the March for Our Lives movement and the success of Democrats in unseating Republicans backed by the National Rifle Association during the 2018 midterm elections. “The best way to seize that momentum with a young, diverse democratic caucus and 18 fewer NRA members of Congress was to run for the White House,” Swalwell said at an afternoon news conference in his East Bay district.

Swalwell began his campaign by declaring to The Atlantic that “gun safety has to be a top 2020 issue,” echoing that point when he went on Stephen Colbert’s late-night TV show with Parkland activist Cameron Kasky.

His signature policy proposal was a mandatory buyback for military-style semiautomatic firearms, making him the only candidate to explicitly support some form of compulsory confiscation — as opposed to bans on production or sale. Swalwell cultivated relationships with prominent gun violence prevention activists, like Fred Guttenberg, whose daughter Jaime was murdered in the 2018 Parkland shooting and who attended the June 28 Democratic debate as Swalwell’s guest. On stage at that debate, Swalwell wore an orange tie and lapel ribbon, a color associated with the gun violence prevention movement.

Despite his single minded focus on gun policy, and his more radical position on buying back military-style semiautomatics, Swalwell was at pains to stand out among the broad Democratic field, who generally share his views and his antipathy toward the NRA.

As The Trace found in its guide to Democratic candidates’ gun policies, no other candidate explicitly announced their support for mandatory buybacks, but every single contender, except tech entrepreneur Andrew Yang, supported an assault weapon ban. Senator Bernie Sanders, whose 2016 campaign against Hillary Clinton was dogged by criticism of past gun-friendly votes, even endorsed an assault weapon buyback, albeit on a voluntary basis. Julian Castro also supported buybacks, though he did not offer a specific plan for implementing them.

Swalwell endorsed several other prominent gun reforms, including a federal gun ownership licensing program — but so did at least 10 other Democratic contenders.