| State: | New Jersey |
| District Number: | 12 |
| Image Caption: | Interactive map of district boundaries since January 3, 2023 |
| Representative: | Bonnie Watson Coleman |
| Party: | Democratic |
| Residence: | Ewing Township |
| Percent Urban: | 97.6 |
| Percent Rural: | 2.4 |
| Population: | 770,752 |
| Population Year: | 2023 |
| Median Income: | $106,709[1] |
| Percent White: | 39.8 |
| Percent Hispanic: | 21.5 |
| Percent Black: | 15.6 |
| Percent Asian: | 19.4 |
| Percent More Than One Race: | 2.8 |
| Percent Other Race: | 0.8 |
| Cpvi: | D+12[2] |
New Jersey's 12th congressional district is represented by Democrat Bonnie Watson Coleman, who has served in Congress since 2015. The district is known for its research centers and educational institutions such as Princeton University, Rider University, The College of New Jersey, Institute for Advanced Study, Johnson & Johnson and Bristol-Myers Squibb. The district is primarily suburban in character, covering portions of Mercer, Somerset, Union, and Middlesex counties, although the district contains the state capital of Trenton as well as the smaller city of Plainfield.
The 12th congressional district (together with the 11th district) was created starting with the 63rd United States Congress in 1913, based on redistricting following the 1910 United States census. Historically, the 12th and its predecessors had been a swing district. However, redistricting following the 2000 United States census gave the district a somewhat bluer hue than its predecessor. It absorbed most of Trenton, along with a number of other municipalities. Since then, the 12th has become a Democratic-leaning district, as measured by the Cook PVI.[3]
The redistricting made second-term Democrat Rush D. Holt Jr. considerably more secure; he had narrowly defeated freshman Republican Michael Pappas in 1998, and had only held on to his seat against Dick Zimmer who represented the district from 1991 to 1997, by 651 votes in 2000. In 2002, despite an expensive challenge from former New Jersey Secretary of State Buster Soaries, Holt was re-elected with 61% of the vote.
The district became even more Democratic after redistricting following the 2010 census, as it lost its share of Republican-leaning Hunterdon County and Monmouth County, while being pushed further into strongly Democratic Middlesex County and gaining the overwhelmingly Democratic Union County town of Plainfield, as well as the portion of Trenton that it had not absorbed in the previous redistricting. Holt retired in 2014 and was succeeded by State Assembly Majority Leader Bonnie Watson Coleman, making her the first African-American woman elected to Congress from New Jersey.
For the 118th and successive Congresses (based on redistricting following the 2020 census), the district contains all or portions of four counties and 32 municipalities.[4]
Mercer County (7)
Ewing Township, Hopewell, Hopewell Township, Pennington, Princeton, Trenton, West Windsor
Middlesex County (14)
Cranbury, Dunellen, East Brunswick, Helmetta, Jamesburg, Middlesex, Milltown, Monroe Township, North Brunswick, Old Bridge Township (part, also 6th), Plainsboro Township, South Brunswick, South River, Spotswood
Somerset County (10)
Bound Brook, Bridgewater (part, also in 7th), Hillsborough (part, also in 7th), Franklin Township, Manville, Millstone, Montgomery, North Plainfield, Rocky Hill, South Bound Brook
Union County (1)
Plainfield
| Year | Office | Results | |
| 2000 | President | Gore 56 - 40% | |
| 2004 | President | Kerry 54 - 46% | |
| 2008 | President | Obama 58 - 41% | |
| 2012 | President | Obama 66.5 - 32% | |
| 2016 | President | Clinton 65 - 32% | |
| 2017 | Governor | Murphy 62.9% - 35.2% | |
| 2020 | President | Biden 67 - 31% | |
| 2020 | Senate | Booker 66.3% - 31.9% | |
| 2021 | Governor | Murphy 62.3% - 36.8% |
| Member | Party | Years | Cong ress | style=min-width:15em | Electoral history | Counties/Towns | ||
|---|---|---|---|---|---|---|---|---|
| District established March 4, 1913 | ||||||||
| align=left | James A. Hamill | Democratic | nowrap | March 4, 1913 – March 3, 1921 | Redistricted from the and re-elected in 1912. Re-elected in 1914. Re-elected in 1916. Re-elected in 1918. Retired. | 1913–1933 Parts of Jersey City | ||
| align=left | Charles F. X. O'Brien | Democratic | nowrap | March 4, 1921 – March 3, 1925 | Elected in 1920. Re-elected in 1922. Retired to become registrar of records of Hudson County. | |||
| align=left | Mary Teresa Norton | Democratic | nowrap | March 4, 1925 – March 3, 1933 | Elected in 1924. Re-elected in 1926. Re-elected in 1928. Re-elected in 1930. Redistricted to the . | |||
| align=left | Frederick R. Lehlbach | Republican | nowrap | March 4, 1933 – January 3, 1937 | Redistricted from the and re-elected in 1932. Re-elected in 1934. Lost re-election. | 1933–1967 Parts of Essex | ||
| align=left | Frank William Towey Jr. | Democratic | nowrap | January 3, 1937 – January 3, 1939 | Elected in 1936. Lost re-election. | |||
| align=left | Robert Kean | Republican | nowrap | January 3, 1939 – January 3, 1959 | Elected in 1938. Re-elected in 1940. Re-elected in 1942. Re-elected in 1944. Re-elected in 1946. Re-elected in 1948. Re-elected in 1950. Re-elected in 1952. Re-elected in 1954. Re-elected in 1956. Retired to run for U.S. senator. | |||
| align=left | George M. Wallhauser | Republican | nowrap | January 3, 1959 – January 3, 1965 | Elected in 1958. Re-elected in 1960. Re-elected in 1962. Retired. | |||
| align=left | Paul J. Krebs | Democratic | nowrap | January 3, 1965 – January 3, 1967 | Elected in 1964. Retired. | |||
| align=left | Florence P. Dwyer | Republican | nowrap | January 3, 1967 – January 3, 1973 | Redistricted from the and re-elected in 1966. Re-elected in 1968. Re-elected in 1970. Retired. | 1967–1973 Parts of Essex and Union | ||
| align=left | Matthew John Rinaldo | Republican | nowrap | January 3, 1973 – January 3, 1983 | Elected in 1972. Re-elected in 1974. Re-elected in 1976. Re-elected in 1978. Re-elected in 1980. Redistricted to the . | 1973–1983 Parts of Union | ||
Jim Courter | Republican | January 3, 1983 – January 3, 1991 | Redistricted from the and re-elected in 1982. Re-elected in 1984. Re-elected in 1986. Re-elected in 1988. Retired. | 1983–1985 Parts of Hunterdon, Morris, Somerset, Sussex, Union, and Warren | ||||
| 1985–1993 Hunterdon and parts of Mercer (Princeton and West Windsor), Middlesex, Morris, Somerset, Sussex, and Warren | ||||||||
Dick Zimmer | Republican | January 3, 1991 – January 3, 1997 | Elected in 1990. Re-elected in 1992. Re-elected in 1994. Retired to run for U.S. senator. | |||||
| 1993–2003 Parts of Hunterdon, Mercer, Middlesex, Monmouth, and Somerset | ||||||||
| align=left | Mike Pappas | Republican | nowrap | January 3, 1997 – January 3, 1999 | Elected in 1996. Lost re-election. | |||
Rush D. Holt Jr. | Democratic | January 3, 1999 – January 3, 2015 | Elected in 1998. Re-elected in 2000. Re-elected in 2002. Re-elected in 2004. Re-elected in 2006. Re-elected in 2008. Re-elected in 2010. Re-elected in 2012. Retired. | |||||
| 2003–2013 Parts of Hunterdon, Mercer, Middlesex, Monmouth, and Somerset | ||||||||
| 2013–2023 Mercer (except Hamilton and Robbinsville), Middlesex (Cranbury, Dunellen, East Brunswick, Helmetta, Jamesburg, Middlesex, Milltown, Monroe, North Brunswick, Plainsboro, South Brunswick, South River, and Spotswood), Somerset (Bound Brook, Franklin Township, Manville and South Bound Brook), and Union (Fanwood, Plainfield, and part of Scotch Plains) | ||||||||
Bonnie Watson Coleman | Democratic | January 3, 2015 – present | Elected in 2014. Re-elected in 2016. Re-elected in 2018. Re-elected in 2020. Re-elected in 2022. Re-elected in 2024. | |||||
| 2023–present: Parts of Mercer, Middlesex, Somerset, and Union (Plainfield) | ||||||||