Mejía, 48, a former head of the Working Families Alliance who had support from Sen. Bernie Sanders and Alexandria Ocasio-Cortez, will fill the seat previously held by Democratic Gov. Mikie Sherrill and serve until January.
Jewish voters make up a key part of the district's electorate, and Hathaway, in the only debate in the special election, claimed Mejia was antisemitic, noting she has said Israel committed genocide in Gaza.
She also campaigned to abolish U.S. Immigration and Customs Enforcement and Medicare for All.
