| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 16,871 | 22,493 | 39,937 | |
| 2020 | R | 17,493 | 22,160 | 40,335 | |
| 2016 | R | 16,057 | 19,648 | 38,478 | |
| 2012 | D | 21,793 | 16,952 | 39,908 | |
| 2008 | D | 23,148 | 17,432 | 41,375 | |
| 2004 | D | 21,421 | 18,597 | 40,085 | |
| 2000 | D | 17,732 | 16,105 | 35,015 | |
| 1996 | D | 16,730 | 12,204 | 33,449 | |
| 1992 | D | 14,531 | 12,459 | 35,828 | |
| 1988 | R | 15,097 | 16,670 | 32,198 | |
| 1984 | R | 13,508 | 19,174 | 33,154 | |
| 1980 | R | 12,343 | 15,628 | 30,470 | |
| 1976 | R | 13,843 | 14,742 | 29,478 | |
| 1972 | R | 10,889 | 16,714 | 28,591 | |
| 1968 | R | 11,388 | 13,023 | 26,849 | |
| 1964 | D | 15,968 | 9,981 | 25,949 | |
| 1960 | R | 10,954 | 15,092 | 26,046 | |
| 1956 | R | 6,276 | 14,771 | 21,047 | |
| 1952 | R | 7,549 | 14,245 | 21,794 | |
| 1948 | R | 8,644 | 9,568 | 18,302 | |
| 1944 | R | 7,753 | 10,663 | 18,416 | |
| 1940 | R | 9,254 | 11,267 | 20,521 | |
| 1936 | D | 10,376 | 6,869 | 18,720 | |
| 1932 | D | 10,765 | 7,666 | 18,843 | |
| 1928 | R | 7,570 | 10,380 | 17,996 | |
| 1924 | R | 2,968 | 7,689 | 14,151 | |
| 1920 | R | 4,831 | 8,755 | 14,039 | |
| 1916 | D | 5,152 | 4,170 | 9,671 | |
| 1912 | D | 3,504 | 2,695 | 8,919 | |
| 1908 | R | 4,983 | 5,366 | 10,702 | |
| 1904 | R | 3,648 | 5,764 | 9,825 | |
| 1900 | R | 4,837 | 5,353 | 10,305 | |
| 1896 | R | 4,641 | 5,442 | 10,233 | |
| 1892 | D | 4,195 | 3,979 | 8,416 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Erie County backed Obama twice but has moved steadily rightward, posting a 14-point Republican margin in 2024 — a pattern common to Rust Belt lakefront counties where manufacturing decline reshaped the electorate.
The Democratic margin in Erie County has rarely exceeded twenty-three points in modern history; the Republican margin has rarely exceeded forty points. 2024 delivered the county to the Republican candidate by fourteen points.
Erie County's demographics resemble the country more than they resemble most counties. A 81% non-Hispanic-white share, a 13% poverty rate, and a median household income of $71,993 — all within the broad national range. The county's voting pattern over the last decade is most similar to that of Lafayette County and Whiteside County.