| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 23,472 | 39,440 | 63,757 | |
| 2020 | R | 22,093 | 35,177 | 58,293 | |
| 2016 | R | 16,737 | 27,614 | 46,065 | |
| 2012 | R | 17,331 | 25,565 | 43,415 | |
| 2008 | R | 16,785 | 23,579 | 40,705 | |
| 2004 | R | 11,563 | 20,922 | 32,571 | |
| 2000 | D | 14,762 | 9,155 | 24,167 | |
| 1996 | R | 8,767 | 11,596 | 21,739 | |
| 1992 | R | 8,473 | 9,751 | 20,932 | |
| 1988 | R | 7,259 | 9,749 | 17,029 | |
| 1984 | R | 7,106 | 11,198 | 18,323 | |
| 1980 | D | 8,791 | 7,284 | 16,295 | |
| 1976 | D | 8,992 | 5,935 | 14,985 | |
| 1972 | R | 3,347 | 10,259 | 13,744 | |
| 1968 | R | 4,007 | 5,184 | 15,722 | |
| 1964 | D | 7,477 | 5,883 | 13,360 | |
| 1960 | D | 7,892 | 5,301 | 13,193 | |
| 1956 | D | 7,421 | 3,998 | 11,419 | |
| 1952 | D | 7,595 | 4,306 | 11,901 | |
| 1948 | D | 6,608 | 1,985 | 8,916 | |
| 1944 | D | 6,579 | 3,191 | 9,770 | |
| 1940 | D | 6,602 | 2,280 | 8,882 | |
| 1936 | D | 8,018 | 2,264 | 10,282 | |
| 1932 | D | 6,346 | 2,617 | 9,012 | |
| 1928 | R | 3,554 | 4,740 | 8,294 | |
| 1924 | D | 3,296 | 2,895 | 6,202 | |
| 1920 | D | 3,919 | 3,311 | 7,230 | |
| 1916 | D | 1,992 | 1,603 | 3,603 | |
| 1912 | D | 1,364 | 148 | 2,553 | |
| 1908 | D | 1,501 | 1,047 | 2,553 | |
| 1904 | D | 1,169 | 723 | 1,923 | |
| 1900 | D | 1,342 | 1,199 | 2,542 | |
| 1896 | D | 1,676 | 1,042 | 2,746 | |
| 1892 | D | 1,222 | 650 | 2,513 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Harnett sits in the Sandhills fringe south of the Triangle, drawing commuters from Raleigh while retaining a rural, military-adjacent character anchored by Fort Liberty's eastern edge — a combination that has kept Republican margins consistently wide.
The shift began with civil rights. 2004 marked the realignment in Harnett County, by a twenty-nine points margin. The Republican margin reached its widest at fifty points in 1972. The 2024 margin was twenty-five points.
The political shift has tracked, in Harnett County, the political shift of the South more broadly. A 62% non-Hispanic-white share, a median household income of $71,287, and a 14% poverty rate describe the demographic context. The county's voting pattern over the last decade is most similar to that of Onslow County and Beaufort County.