As of the census of 2000, there were 20,527 people, 6,486 households, and 4,682 families residing in the city. The population density was 1,021.8 people per square mile (394.5/km²). There were 7,109 housing units at an average density of 353.9/sq mi (136.6/km²). The racial makeup of the city was 92.06% White, 2.53% African American, 1.11% Native American, 0.47% Asian, 0.33% Pacific Islander, 1.65% from other races, and 1.86% from two or more races. Hispanic or Latino of any race were 4.14% of the population.

There were 6,486 households out of which 39.0% had children under the age of 18 living with them, 59.8% were married couples living together, 9.1% had a female householder with no husband present, and 27.8% were non-families. 16.3% of all households were made up of individuals and 5.8% had someone living alone who is 65 years of age or older. The average household size was 3.07 and the average family size was 3.37.

In the city the population was spread out with 28.2% under the age of 18, 27.4% from 18 to 24, 22.6% from 25 to 44, 14.0% from 45 to 64, and 7.8% who were 65 years of age or older. The median age was 23 years. For every 100 females there were 95.6 males. For every 100 females age 18 and over, there were 91.0 males..

The median income for a household in the city was $32,403, and the median income for a family was $37,509. Males had a median income of $31,192 versus $19,601 for females. The per capita income for the city was $14,057. About 14.5% of the families and 22.1% of the population were below the poverty line, including 20.2% of those under the age of 18 and 4.2% of those 65 and older.