| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 7,726 | 4,047 | 12,187 | |
| 2020 | D | 7,554 | 4,278 | 12,293 | |
| 2016 | D | 5,562 | 3,359 | 10,885 | |
| 2012 | D | 5,191 | 4,796 | 10,654 | |
| 2008 | D | 5,824 | 5,064 | 11,069 | |
| 2004 | R | 5,206 | 5,810 | 11,197 | |
| 2000 | R | 4,149 | 5,623 | 10,218 | |
| 1996 | R | 3,983 | 4,999 | 9,932 | |
| 1992 | R | 3,897 | 4,320 | 10,642 | |
| 1988 | R | 3,275 | 6,622 | 10,153 | |
| 1984 | R | 2,859 | 6,882 | 9,888 | |
| 1980 | R | 2,368 | 5,460 | 9,383 | |
| 1976 | R | 2,890 | 5,383 | 8,355 | |
| 1972 | R | 2,435 | 5,039 | 7,624 | |
| 1968 | R | 2,552 | 3,447 | 6,276 | |
| 1964 | D | 3,767 | 1,895 | 5,688 | |
| 1960 | D | 2,692 | 2,574 | 5,283 | |
| 1956 | R | 2,214 | 2,406 | 4,629 | |
| 1952 | D | 2,281 | 2,226 | 4,515 | |
| 1948 | — | — | — | — | |
| 1944 | — | — | — | — | |
| 1940 | — | — | — | — | |
| 1936 | — | — | — | — | |
| 1932 | — | — | — | — | |
| 1928 | — | — | — | — | |
| 1924 | — | — | — | — | |
| 1920 | — | — | — | — | |
| 1916 | — | — | — | — | |
| 1912 | — | — | — | — | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Home to Los Alamos National Laboratory, this small county posts one of New Mexico's widest Democratic margins, driven by a workforce of scientists and engineers that skews heavily toward advanced degrees.
The 2008 election was the turning point, when the Democratic candidate carried the county by seven points. The 2024 margin was thirty points, in line with the county's new direction.
The demographics suggest why. A population of 19,435, a 75% non-Hispanic-white share, and a median household income of $147,139 situate the county in the broader realignment patterns of recent cycles. The county's voting pattern over the last decade is most similar to that of Mono County and Rockdale County.
