The International Longshore and Warehouse Union has endorsed state Senate President Donna Mercado Kim’s bid for Congress.

The ILWU Local 142 represents 18,000 members and is the largest private-sector union in Hawaii. It represents longshore workers, truck drivers, heavy equipment operators, housekeepers and others.

Union officials said Kim’s background — growing up in a working-class neighborhood — means she shares many of the same life experiences and values as many of its members.

Kim is running for the 1st Congressional District (urban Hono-lulu) seat being vacated by incumbent U.S. Rep. Colleen Hana-busa, who is running for U.S. Senate. Others in the Demo-cratic primary are Hono-lulu City Council members Ikaika Anderson, Stanley Chang and Joey Mana-han; state Sen. Will Espero (D, Ewa Beach-Iroquois Point); state Rep. Mark Takai (D, Halawa-Newton-Aiea); and social activist Kathryn Xian.

Kim is midway through a four-year state Senate term and does not need to give up her seat to run for Congress.