| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 9,137 | 2,745 | 12,209 | |
| 2020 | D | 9,914 | 2,631 | 12,873 | |
| 2016 | D | 8,400 | 2,477 | 11,851 | |
| 2012 | D | 7,978 | 2,792 | 10,968 | |
| 2008 | D | 7,913 | 2,442 | 10,553 | |
| 2004 | D | 7,265 | 2,602 | 9,997 | |
| 2000 | D | 5,474 | 2,315 | 8,856 | |
| 1996 | D | 5,137 | 1,739 | 7,702 | |
| 1992 | D | 4,292 | 1,827 | 7,888 | |
| 1988 | D | 4,495 | 2,441 | 7,025 | |
| 1984 | D | 3,313 | 2,788 | 6,125 | |
| 1980 | D | 2,370 | 1,809 | 5,397 | |
| 1976 | D | 2,513 | 2,365 | 5,135 | |
| 1972 | R | 2,001 | 2,312 | 4,336 | |
| 1968 | R | 1,540 | 1,576 | 3,196 | |
| 1964 | D | 2,187 | 1,015 | 3,214 | |
| 1960 | R | 1,282 | 1,998 | 3,286 | |
| 1956 | R | 541 | 2,618 | 3,160 | |
| 1952 | R | 760 | 2,432 | 3,198 | |
| 1948 | R | 720 | 1,731 | 2,484 | |
| 1944 | R | 861 | 1,372 | 2,234 | |
| 1940 | R | 1,014 | 1,643 | 2,670 | |
| 1936 | R | 931 | 1,655 | 2,615 | |
| 1932 | R | 583 | 1,330 | 1,933 | |
| 1928 | R | 470 | 1,487 | 1,958 | |
| 1924 | R | 108 | 1,182 | 1,360 | |
| 1920 | R | 150 | 1,013 | 1,168 | |
| 1916 | R | 309 | 464 | 787 | |
| 1912 | R | 215 | 269 | 774 | |
| 1908 | R | 133 | 589 | 767 | |
| 1904 | R | 120 | 602 | 751 | |
| 1900 | R | 114 | 617 | 780 | |
| 1896 | R | 91 | 691 | 858 | |
| 1892 | R | 238 | 588 | 884 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
This island county's seasonal population swells well beyond its 15,000 year-round residents, but its electorate consistently tilts heavily Democratic — the 2024 presidential margin of D+52 ranks among the most lopsided in Massachusetts.
The unraveling was not abrupt. The Democratic margin in Dukes County peaked at fifty-seven points in 2020; it narrowed steadily over the late twentieth century. The 1976 election delivered the county to the Republican party for the first time in many years, by a margin of three points. By 2024, the margin had widened further.
The economic and demographic context is severe. Dukes County's median household income of $125,786 is among the lowest of any county in the United States; 4% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Hampshire County and Orleans Parish.