| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 77,832 | 62,524 | 142,880 | |
| 2020 | D | 81,287 | 60,490 | 144,926 | |
| 2016 | D | 63,890 | 56,876 | 128,303 | |
| 2012 | D | 69,393 | 48,066 | 119,392 | |
| 2008 | D | 77,232 | 50,627 | 129,590 | |
| 2004 | D | 68,262 | 52,231 | 122,969 | |
| 2000 | D | 62,610 | 42,712 | 113,170 | |
| 1996 | D | 56,418 | 34,242 | 107,148 | |
| 1992 | D | 51,552 | 36,057 | 122,347 | |
| 1988 | R | 50,749 | 54,633 | 106,719 | |
| 1984 | R | 40,227 | 65,342 | 106,093 | |
| 1980 | R | 38,122 | 48,923 | 102,028 | |
| 1976 | R | 47,992 | 48,685 | 97,281 | |
| 1972 | R | 34,812 | 60,268 | 95,995 | |
| 1968 | D | 43,531 | 38,320 | 86,865 | |
| 1964 | D | 57,240 | 25,135 | 82,426 | |
| 1960 | D | 42,900 | 39,441 | 82,342 | |
| 1956 | R | 28,854 | 45,579 | 74,433 | |
| 1952 | R | 33,132 | 40,097 | 73,386 | |
| 1948 | D | 31,253 | 28,977 | 61,226 | |
| 1944 | D | 31,024 | 25,522 | 56,839 | |
| 1940 | D | 30,075 | 24,803 | 54,981 | |
| 1936 | D | 26,447 | 22,749 | 50,648 | |
| 1932 | D | 20,903 | 20,776 | 42,540 | |
| 1928 | R | 17,498 | 22,463 | 40,253 | |
| 1924 | R | 9,349 | 19,324 | 31,138 | |
| 1920 | R | 9,831 | 18,392 | 29,113 | |
| 1916 | R | 8,721 | 8,780 | 17,981 | |
| 1912 | D | 7,215 | 5,917 | 16,554 | |
| 1908 | R | 6,787 | 10,506 | 17,764 | |
| 1904 | R | 7,349 | 10,924 | 18,658 | |
| 1900 | R | 7,036 | 10,162 | 17,497 | |
| 1896 | R | 3,412 | 8,745 | 13,019 | |
| 1892 | — | — | — | — | |
| 1888 | R | 7,889 | 8,236 | 16,728 | |
| 1884 | R | 6,861 | 7,908 | 14,769 | |
| 1880 | R | 6,982 | 8,484 | 15,465 | |
| 1876 | R | 6,961 | 7,861 | 14,822 |
Southeastern Connecticut Planning Region sits in New England. Its political identity has been Democratic for as long as anyone now living can remember. 5 consecutive presidential elections in modern records have gone for the Democratic candidate, often by margins that would be considered landslide territory anywhere else.
The Democratic margin in Southeastern Connecticut Planning Region reached its widest at thirty-nine points in 1964. The margin in 2024 was eleven points — still decisive.
Southeastern Connecticut Planning Region's loyalty is rooted in its place. Median household income of $86,586, a 74% non-Hispanic-white share, and a population of 279,971 together describe a community whose political habits are deeply settled. The county's voting pattern over the last decade is most similar to that of Lower Connecticut River Valley Planning Region and Naugatuck Valley Planning Region.
