| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 2,848 | 2,804 | 5,745 | |
| 2020 | D | 3,346 | 2,714 | 6,158 | |
| 2016 | D | 3,353 | 2,497 | 5,964 | |
| 2012 | D | 3,780 | 2,529 | 6,394 | |
| 2008 | D | 3,567 | 2,522 | 6,184 | |
| 2004 | D | 3,173 | 2,235 | 5,508 | |
| 2000 | D | 3,059 | 1,965 | 5,254 | |
| 1996 | D | 3,692 | 1,455 | 5,608 | |
| 1992 | D | 3,416 | 1,515 | 5,618 | |
| 1988 | D | 3,013 | 2,006 | 5,153 | |
| 1984 | D | 2,956 | 2,366 | 5,435 | |
| 1980 | D | 3,183 | 1,531 | 4,852 | |
| 1976 | D | 2,622 | 1,046 | 3,788 | |
| 1972 | R | 943 | 1,446 | 2,781 | |
| 1968 | D | 1,351 | 219 | 3,370 | |
| 1964 | D | 1,319 | 706 | 2,025 | |
| 1960 | D | 678 | 296 | 1,809 | |
| 1956 | D | 997 | 545 | 1,689 | |
| 1952 | D | 895 | 586 | 1,481 | |
| 1948 | D | 469 | 59 | 1,191 | |
| 1944 | D | 683 | 108 | 791 | |
| 1940 | D | 1,007 | 80 | 1,087 | |
| 1936 | D | 1,199 | 102 | 1,301 | |
| 1932 | D | 962 | 26 | 988 | |
| 1928 | D | 609 | 145 | 754 | |
| 1924 | D | 185 | 18 | 203 | |
| 1920 | D | 366 | 36 | 402 | |
| 1916 | D | 319 | 9 | 334 | |
| 1912 | D | 214 | 13 | 241 | |
| 1908 | D | 281 | 34 | 316 | |
| 1904 | D | 234 | 30 | 265 | |
| 1900 | — | 0 | 0 | 0 | |
| 1896 | D | 522 | 59 | 589 | |
| 1892 | D | 306 | 77 | 383 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
St. Helena Parish, a sparsely populated piney-woods community northeast of Baton Rouge, defied Louisiana's broader Republican tilt in 2024, producing a margin under a single percentage point — a rarity in a state that otherwise moved decisively.
The county's recent history is a story of close margins. The Democratic margin reached ninety-five points in 1932; the Republican margin reached eighteen points in 1972. Most other elections have been decided by single-digit points.
St. Helena Parish's demographics — a population of 10,858, a 45% non-Hispanic-white share, a median household income of $41,934 — situate the county close to national averages on several dimensions. The county's voting pattern over the last decade is most similar to that of Lee County and Clay County.
