| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 499,551 | 140,789 | 669,800 | |
| 2020 | D | 617,659 | 136,309 | 773,753 | |
| 2016 | D | 514,842 | 95,922 | 659,543 | |
| 2012 | D | 469,684 | 108,182 | 596,893 | |
| 2008 | D | 489,106 | 119,555 | 622,913 | |
| 2004 | D | 422,585 | 130,911 | 562,090 | |
| 2000 | D | 342,889 | 119,279 | 494,336 | |
| 1996 | D | 303,903 | 106,581 | 462,044 | |
| 1992 | D | 334,224 | 109,292 | 530,145 | |
| 1988 | D | 310,283 | 162,815 | 478,997 | |
| 1984 | D | 282,041 | 192,408 | 480,874 | |
| 1980 | D | 201,720 | 158,531 | 417,617 | |
| 1976 | D | 235,988 | 155,280 | 407,681 | |
| 1972 | D | 259,254 | 201,862 | 471,195 | |
| 1968 | D | 219,545 | 153,285 | 407,349 | |
| 1964 | D | 283,833 | 142,998 | 427,340 | |
| 1960 | D | 217,172 | 183,354 | 402,000 | |
| 1956 | R | 174,033 | 192,911 | 368,131 | |
| 1952 | R | 173,853 | 192,941 | 369,776 | |
| 1948 | D | 154,549 | 150,588 | 323,331 | |
| 1944 | D | 169,631 | 122,982 | 293,987 | |
| 1940 | D | 148,224 | 116,961 | 268,496 | |
| 1936 | D | 149,323 | 82,352 | 234,686 | |
| 1932 | D | 106,388 | 89,303 | 204,452 | |
| 1928 | R | 60,875 | 118,539 | 181,194 | |
| 1924 | R | 8,020 | 81,454 | 132,490 | |
| 1920 | R | 21,468 | 73,177 | 105,889 | |
| 1916 | R | 43,748 | 51,417 | 102,131 | |
| 1912 | D | 24,418 | 0 | 66,452 | |
| 1908 | R | 7,110 | 21,380 | 33,283 | |
| 1904 | R | 4,399 | 19,065 | 27,110 | |
| 1900 | R | 6,677 | 14,324 | 22,159 | |
| 1896 | R | 8,394 | 13,429 | 22,223 | |
| 1892 | R | 7,114 | 8,792 | 18,470 | |
| 1888 | R | 5,693 | 8,840 | 15,461 | |
| 1884 | R | 4,734 | 7,471 | 12,398 | |
| 1880 | R | 3,894 | 5,897 | 9,897 | |
| 1876 | R | 3,347 | 4,938 | 8,297 |
Alameda's dense urban core around Oakland and Berkeley anchors a Democratic presidential margin that has exceeded 50 points in recent cycles, making it a reliable high-turnout base rather than a competitive battleground.
The Democratic margin in Alameda County has been steady. It reached its modern peak at sixty-four points in 2016; the 2024 margin was fifty-four points, still in line with the county's long pattern.
Alameda County's political identity is inseparable from its demographic profile: a 30% non-Hispanic-white share, a median household income of $129,367, and the full diversity of a major metropolitan center. The county's voting pattern resembles other major urban centers most closely — Holmes County and Santa Fe County.
