As of the census of 2000, 313,645 people, 110,365 households, and 79,683 families resided in the county. The population density was 375 people per square mile. The 123,041 housing units averaged 147 per square mile. The racial makeup of the county was 72.03% White, 4.24% African American, 0.64% Native American, 1.16% Asian, 0.07% Pacific Islander, 18.74% from other races, and 3.13% from two or more races. About 55.78% of the population was Hispanic or Latino of any race. Of the 110,365 households, 36.30% had children under the age of 18 living with them, 51.80% were married couplesliving together, 15.30% had a female householder with no husband present, and 27.80% were not families. About 22.60% of all households were made up of individuals, and 7.90% had someone living alone who was 65 years of age or older. The average household size was 2.79 and the average family size was 3.30. In the county, the population was distributed as 28.40% under the age of 18, 10.50% from 18 to 24, 28.90% from 25 to 44, 21.10% from 45 to 64, and 11.20% who were 65 years of age or older. The median age was 33 years. For every 100 females, there were 95.80 males. For every 100 females age 18 and over, there were 92.50 males. The median income for a household in the county was $35,959, and for a family was $41,066. Males had a median income of $31,571 versus $22,324 for females. The per capita income for the county was $17,036. About 14.70% of families and 18.20% of the population were below the poverty line, including 24.00% of those under age 18 and 15.80% of those age 65 or over.
Historically, Nueces County leaned Democratic in presidential elections, though in recent years has narrowly voted Republican. Dwight D. Eisenhower in 1952 became the first Republican candidate to carry the county. Prior to that year, the only times Nueces County did not vote for the national Democratic candidate was in its first presidential election in 1848 for WhigZachary Taylor, and in 1860, supporting Southern Democratic John C. Breckinridge. Since Eisenhower's election, the only other Republicans to carry the county in the 20th century were Richard Nixon in 1972 and Ronald Reagan in 1984. So far, Bill Clinton remains the last Democratic candidate to win Nueces County, having done so in 1996. Since 2000, Nueces County has voted for every Republican presidential candidate, with only George W. Bush in 2004 having carried it by a double digit margin, and his 56.8% of the vote is also the highest for any Republican in the county's history. In 2016, Donald Trump defeated Hillary Clinton in the county 48.6% to 47.1%, or 1,568 votes, the closest race since 1956. The results of the 2016 election made Nueces County the southernmost county in the entire country to have been won by Donald Trump. Democratic strength is concentrated within the inland portion of the county, with particular strengths in downtown Corpus Christi plus the city's heavily Hispanic neighborhoods, Robstown, and communities in the western part of the county. Republicans generally do well with areas closer to the coast, particularly in the southeast suburb of Corpus Christi, Flour Bluff, and Port Aransas.
