As of the 2010 United States Census, the district had a population of 222,972, of whom 175,967 (76.5%) were of voting age. The racial makeup of the district was 208,724 (90.8%) White, 7,216 (3.1%) African American, 319 (0.1%) Native American, 6,670 (2.9%) Asian, 67 (0.0%) Pacific Islander, 3,484 (1.5%) from some other race, and 3,492 (1.5%) from two or more races. Hispanic or Latino of any race were 14,158 (6.2%) of the population.[3] The 23rd District had 141,223 registered voters as of November 2015, of whom 64,774 (45.9%) were registered as unaffiliated, 29,470 (20.9%) were registered as Democrats, 46,800 (33.1%) were registered as Republicans and 179 (0.1%) were registered to other parties.[4]
As of 2000, the district had the largest population of any in the state and the second-highest land area, making it one of the least densely populated districts in the state. The district had a small minority population, with comparatively few African American, Asian and Hispanic residents. The district had the highest municipal tax rate in the state, but lower than average school and county taxes leave the overall rate near the statewide median. Registered Republicans outnumber Democrats by a 2-1 margin.[5][6]
In the 2001 redistricting, the Mercer County municipalities were eliminated from the 23rd with the district only consisting of Hunterdon County save for Tewksbury Township and Califon and all of Warren County.[10] The district experienced a major change following the 2011 redistricting; the 23rd currently consists of southern Warren County including Phillipsburg, Washington, and Hackettstown, most of northern Hunterdon County, and a spur into Somerset County via Bedminster, Peapack-Gladstone, Bridgewater, Raritan Borough, Bound Brook, and South Bound Brook.
Despite the historic Republican nature of Morris County, Democrats swept the three legislative seats up for election in 1973: Stephen B. Wiley, who was also elected in a special election to complete an unexpired Senate term under the old at-large Morris County district, was elected to a four-year Senate term from this district, Gordon MacInnes and Rosemarie Totaro won both Assembly seats as well.[13] MacInnes and Totaro would both be defeated for re-election in 1975 but Totaro would again serve one term in the Assembly after winning in 1977 and MacInnes would later serve four years in the Senate from the geographically-similar 25th District in 1993. Governor of New JerseyBrendan Byrne nominated State Senator Wiley to the New Jersey Supreme Court in 1977, his nomination was approved by the Senate, but was rejected by the Supreme Court, which ruled that as Wiley had voted to raise the salary of justices of the Supreme Court in 1974, he could not be appointed to serve on the court until after his term of office expired.[14] Wiley served the remainder of his term in the Senate but was defeated for re-election in 1977 by Republican John H. Dorsey.
On January 24, 2009, a special election was held by a convention of Republican committee members from Hunterdon and Warren counties to fill the Senate vacancy created when Leonard Lance was elected to Congress. Marcia A. Karrow defeated Michael J. Doherty in the special election by a margin of 195 votes to 143. Doherty announced he would run against Karrow a second time in the June 2009 primary, when she would be running as the incumbent.[16]
The Hunterdon and Warren County Republican committee members held another special convention on February 21, 2009 to fill Karrow's vacant Assembly seat. In the contest, Warren County FreeholderJohn DiMaio defeated Hunterdon County Freeholders Matt Holt and Erik Peterson.[17][18]
On June 2, 2009, Doherty defeated Karrow in the Republican Senate primary by a margin of 52%-48%, making her the only incumbent to lose a primary battle that year.[19] Doherty went on to win the November special election, defeating Democratic candidate Harvey Baron to fill the remaining two years of the term.[20] Karrow's Senate term ended on November 23, 2009 when Doherty was sworn into office.[21]
Senators and Assembly members elected from the district are as follows:[22]
^Edge, Wally (February 18, 2009). "Through parts of four decades, ten districts that have never flipped". Politicker NJ. Retrieved July 26, 2015. District 25: [sic] Democrats have won a few times in heavily Republican Morris County. They swept in 1973, when Stephen Wiley won a State Senate seat and Gordon MacInnes and Rosemarie Totaro went to the Assembly after beating John Dorsey and Assemblyman Albert Merck.