Adam Hamawy (D) defeated 12 other candidates in the Democratic primary for New Jersey's 12th Congressional District on June 2, 2026. Ahead of the Democratic primary, Susan Altman (D), Brad Cohen (D), Hamawy, Adrian Mapp (D), Verlina Reynolds-Jackson (D), Shanel Robinson (D), and Jay Vaingankar (D) led in endorsements and media attention.

Incumbent Rep. Bonnie Watson Coleman (D) did not run for re-election. She did not endorse a candidate in the Democratic primary. As of June 2, 2026, The Cook Political Report with Amy Walter and Inside Elections with Nathan L. Gonzales rated the general election as Solid Democratic. Larry J. Sabato's Crystal Ball rated it as Safe Democratic.

Rider University's Micah Rasmussen said that Watson Colemon's retirement and the historical precedent that the incumbent president's party typically loses seats in the U.S. House of Representatives in midterm elections led to a large number of candidates running in the Democratic primary.

According to the New Jersey Globe’s Joey Fox, the seven noteworthy candidates mentioned above all had viable paths to winning the nomination. Fox also wrote that Cohen, Mapp, Reynolds-Jackson, and Robinson had support in the areas that they represented in their elected positions heading into the Democratic primary. The Democratic Committees in the four counties the district covers have endorsed different candidates. According to the New Jersey Globe's Zach Blackburn, the split in committee endorsements means that "[n]o candidate has dominant establishment support.

Below is a background on each candidate. To read more about how Ballotpedia defines noteworthy candidates, click here.

• Altman ran unsuccessfully for New Jersey's 7th Congressional District in 2024. She previously worked as the executive director of the New Jersey Working Families Party and as state director for U.S. Sen. Andrew Kim (D-N.J.). The College Democrats of New Jersey endorsed Altman.
• Cohen was, at the time of the primary, a physician and surgeon who was first elected mayor of East Brunswick in 2016. He previously served on the East Brunswick Board of Education from 2010 to 2016. The Middlesex County Democratic Committee endorsed Cohen.
• Hamawy was, at the time of the primary, a surgeon and business owner who served in the U.S. Army from 2003 to 2011. U.S. Sen. Tammy Duckworth (D-Ill.) endorsed Hamawy. In 2004, Hamawy operated on Duckworth following an attack on her helicopter in Iraq.
• Mapp was, at the time of the primary, an accountant who was first elected mayor of Plainfield in 2013. He previously served on the Union County Board of Freeholders from 2005 to 2007, and on the Plainfield City Council from 1999 to 2006 and from 2009 to 2013.
• Reynolds-Jackson was appointed to the New Jersey General Assembly in 2018. She previously served on the Trenton City Council from 2010 to 2018 and worked as a social worker. The Mercer County Democratic Committee endorsed Reynolds-Jackson.
• Robinson was first elected to the Somerset County Board of Commissioners in 2018. She previously served on the Franklin City Council from 2015 to 2018 and worked as a borough administrator. Robinson also served in the U.S. Air Force from 1989 to 1998. The Somerset County Democratic Committee endorsed Robinson.
• Vaingankar was, at the time of the primary, a community organizer who worked as a special advisor in the Secretary’s Office of Policy for the U.S. Department of Energy under President Joe Biden (D). Former U.S. Secretary of Energy Jennifer Granholm (D) endorsed Vaingankar.

Matt Adams (D), Elijah Dixon (D), Kyle Little (D), Squire Servance (D), Sujit Singh (D), and Samuel Wang (D) also ran in the primary.