| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 1,807 | 10,559 | 12,478 | |
| 2020 | R | 2,160 | 10,373 | 12,683 | |
| 2016 | R | 2,012 | 9,235 | 11,496 | |
| 2012 | R | 2,742 | 8,498 | 11,365 | |
| 2008 | R | 2,985 | 9,072 | 12,195 | |
| 2004 | R | 2,839 | 7,906 | 10,819 | |
| 2000 | R | 3,094 | 6,087 | 9,311 | |
| 1996 | R | 3,316 | 4,375 | 8,555 | |
| 1992 | R | 3,714 | 5,173 | 9,742 | |
| 1988 | R | 3,044 | 5,511 | 8,591 | |
| 1984 | R | 2,766 | 5,837 | 8,617 | |
| 1980 | D | 5,001 | 3,545 | 8,715 | |
| 1976 | D | 5,021 | 2,507 | 7,659 | |
| 1972 | R | 658 | 5,477 | 6,230 | |
| 1968 | R | 624 | 948 | 6,770 | |
| 1964 | R | 1,237 | 2,939 | 4,176 | |
| 1960 | D | 2,001 | 605 | 3,295 | |
| 1956 | D | 2,882 | 427 | 3,494 | |
| 1952 | D | 2,749 | 917 | 3,666 | |
| 1948 | D | 478 | 63 | 1,964 | |
| 1944 | D | 2,140 | 183 | 2,323 | |
| 1940 | D | 2,609 | 108 | 2,726 | |
| 1936 | D | 2,249 | 63 | 2,316 | |
| 1932 | D | 2,264 | 74 | 2,346 | |
| 1928 | D | 1,858 | 324 | 2,182 | |
| 1924 | D | 1,750 | 135 | 1,971 | |
| 1920 | D | 1,224 | 429 | 1,665 | |
| 1916 | D | 1,666 | 89 | 1,763 | |
| 1912 | D | 962 | 23 | 1,078 | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | D | 1,151 | 189 | 1,359 | |
| 1896 | D | 1,262 | 114 | 1,383 | |
| 1892 | D | 721 | 14 | 1,175 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Union County's R+70.1 margin in 2024 placed it among the most one-sided counties in the state, reflecting the rural, predominantly white demographic pattern common to northeastern Mississippi's hill country.
The unraveling was not abrupt. The Democratic margin in Union County peaked at ninety-four points in 1936; it narrowed steadily over the late twentieth century. The 1984 election delivered the county to the Republican party for the first time in many years, by a margin of thirty-six points. By 2024, the margin had widened further.
The economic and demographic context is severe. Union County's median household income of $55,505 is among the lowest of any county in the United States; 15% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Tipton County and Covington County.
