| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 306 | 1,503 | 1,847 | |
| 2020 | R | 349 | 1,489 | 1,870 | |
| 2016 | R | 270 | 1,202 | 1,590 | |
| 2012 | R | 396 | 1,173 | 1,614 | |
| 2008 | R | 479 | 1,275 | 1,804 | |
| 2004 | R | 440 | 1,359 | 1,820 | |
| 2000 | R | 335 | 1,295 | 1,688 | |
| 1996 | R | 674 | 861 | 1,880 | |
| 1992 | D | 674 | 593 | 1,778 | |
| 1988 | D | 807 | 786 | 1,612 | |
| 1984 | R | 648 | 1,000 | 1,666 | |
| 1980 | R | 774 | 1,088 | 2,053 | |
| 1976 | D | 898 | 824 | 1,768 | |
| 1972 | R | 635 | 961 | 1,687 | |
| 1968 | D | 927 | 697 | 1,801 | |
| 1964 | D | 1,557 | 487 | 2,044 | |
| 1960 | D | 1,432 | 781 | 2,213 | |
| 1956 | D | 1,292 | 833 | 2,125 | |
| 1952 | D | 1,276 | 1,004 | 2,280 | |
| 1948 | D | 1,224 | 487 | 1,763 | |
| 1944 | D | 1,222 | 589 | 1,811 | |
| 1940 | D | 1,462 | 729 | 2,198 | |
| 1936 | D | 1,612 | 507 | 2,168 | |
| 1932 | D | 1,390 | 526 | 1,957 | |
| 1928 | R | 793 | 1,146 | 1,964 | |
| 1924 | R | 601 | 650 | 2,004 | |
| 1920 | R | 712 | 1,013 | 1,732 | |
| 1916 | D | 1,255 | 901 | 2,294 | |
| 1912 | D | 1,131 | 436 | 2,569 | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Lewis County's roughly 3,700 residents are spread across rolling Camas Prairie farmland, and its electorate has tilted Republican by double digits for decades — reaching a 65-point margin in 2024.
The unraveling was not abrupt. The Democratic margin in Lewis County peaked at fifty-two points in 1964; it narrowed steadily over the late twentieth century. The 1996 election delivered the county to the Republican party for the first time in many years, by a margin of ten points. By 2024, the margin had widened further.
The economic and demographic context is severe. Lewis County's median household income of $51,615 is among the lowest of any county in the United States; 15% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Lincoln County and Clearwater County.