New Jersey's 12th congressional district

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 United States Census, 1910.

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.

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.

Since then, the 12th has become a Democratic-leaning district, as measured by the Cook PVI.[3] In 2004, Holt was re-elected over real estate executive Bill Spadea (59–41%) and again in 2006 over former Helmetta Council President Joseph Sinagra (65–35%).

In 2008, Holt defeated Holmdel Township Deputy Mayor Alan Bateman (62–36%).

In 2010, while Democrats suffered huge House loses, Holt defeated Princeton venture capitalist Scott Sipprelle and Independent Kenneth J. Cody (53–46–1%).

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.

For the 113th and successive Congresses (based on redistricting following the 2010 Census), the congressional district contains portions of four counties and 31 municipalities:[4]

Mercer County (10)

East Windsor Township, Ewing Township, Hightstown, Hopewell Borough, Hopewell Township, Lawrence Township, Pennington, Princeton, Trenton and West Windsor Township

Middlesex County (14)

Cranbury Township, Dunellen, East Brunswick Township, Helmetta, Jamesburg, Middlesex, Milltown, Monroe Township, North Brunswick Township, Old Bridge Township (part, also 6th), Plainsboro Township, South Brunswick Township, South River Borough, and Spotswood Borough

Somerset County (4)

Bound Brook, Franklin Township, Manville and South Bound Brook

Union County (3)

Fanwood, Plainfield, Scotch Plains (part, also 7th)

• Martis, Kenneth C. (1989). The Historical Atlas of Political Parties in the United States Congress. New York: Macmillan Publishing Company.
• Martis, Kenneth C. (1982). The Historical Atlas of United States Congressional Districts. New York: Macmillan Publishing Company.
• Congressional Biographical Directory of the United States 1774–present