| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 12,794 | 13,161 | 26,759 | |
| 2020 | D | 14,941 | 13,123 | 28,986 | |
| 2016 | D | 11,500 | 10,603 | 24,684 | |
| 2012 | D | 13,163 | 9,200 | 23,391 | |
| 2008 | D | 14,854 | 9,935 | 25,629 | |
| 2004 | D | 13,141 | 11,093 | 24,719 | |
| 2000 | D | 10,717 | 8,699 | 20,919 | |
| 1996 | D | 10,432 | 7,458 | 21,335 | |
| 1992 | D | 10,548 | 6,678 | 23,213 | |
| 1988 | D | 9,828 | 9,366 | 19,502 | |
| 1984 | R | 8,648 | 10,874 | 19,831 | |
| 1980 | R | 5,978 | 8,934 | 16,654 | |
| 1976 | D | 6,374 | 5,462 | 12,285 | |
| 1972 | R | 4,715 | 6,477 | 11,750 | |
| 1968 | R | 3,777 | 4,464 | 9,111 | |
| 1964 | D | 4,680 | 3,616 | 8,302 | |
| 1960 | R | 2,897 | 4,176 | 7,109 | |
| 1956 | R | 2,185 | 4,073 | 6,282 | |
| 1952 | R | 1,911 | 4,113 | 6,087 | |
| 1948 | R | 1,999 | 3,054 | 5,333 | |
| 1944 | R | 1,671 | 2,059 | 3,746 | |
| 1940 | R | 1,897 | 2,215 | 4,151 | |
| 1936 | D | 1,837 | 1,797 | 3,687 | |
| 1932 | D | 2,344 | 1,301 | 3,744 | |
| 1928 | R | 926 | 1,820 | 2,784 | |
| 1924 | R | 261 | 795 | 1,769 | |
| 1920 | R | 571 | 993 | 1,735 | |
| 1916 | D | 1,164 | 791 | 2,233 | |
| 1912 | D | 1,118 | 0 | 2,156 | |
| 1908 | D | 628 | 625 | 1,459 | |
| 1904 | R | 594 | 641 | 1,412 | |
| 1900 | D | 746 | 584 | 1,409 | |
| 1896 | D | 854 | 546 | 1,437 | |
| 1892 | D | 644 | 532 | 1,432 | |
| 1888 | D | 867 | 731 | 1,629 | |
| 1884 | D | 798 | 588 | 1,391 | |
| 1880 | D | 677 | 454 | 1,141 | |
| 1876 | D | 702 | 380 | 1,085 |
Lake County, anchored by Clear Lake and dependent on agriculture and tourism, has swung from reliably Democratic to near-even territory since 2004, making it a rare competitive marker in California's otherwise lopsided interior counties.
The county's recent history is a story of close margins. The Democratic margin reached fifty-two points in 1912; the Republican margin reached thirty-six points in 1952. Most other elections have been decided by single-digit points.
Lake County's demographics — a population of 68,152, a 68% non-Hispanic-white share, a median household income of $60,621 — 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 Erie County and Cibola County.
