| County | Election Day Registrants | Total Registered Voters | Ballots Cast | Percentage |
|---|---|---|---|---|
| Ada | 13,018 | 162,683 | 93,509 | 57.5 % |
| Adams | 81 | 2,573 | 1,705 | 66.3 % |
| Bannock | 2,984 | 40,143 | 23,471 | 58.5 % |
| Bear Lake | 124 | 3,580 | 2,074 | 57.9 % |
| Benewah | 123 | 4,849 | 2,951 | 60.9 % |
| Bingham | 1,119 | 20,083 | 11,903 | 59.3 % |
| Blaine | 273 | 10,520 | 5,575 | 53.0 % |
| Boise | 218 | 4,496 | 2,309 | 51.4 % |
| Bonner | 892 | 19,241 | 11,382 | 59.2 % |
| Bonneville | 2,708 | 42,714 | 25,786 | 60.4 % |
| Boundary | 251 | 5,393 | 3,172 | 58.8 % |
| Butte | 26 | 1,984 | 1,227 | 61.8 % |
| Camas | 34 | 662 | 455 | 68.7 % |
| Canyon | 2,753 | 54,900 | 33,481 | 61.0 % |
| Caribou | 107 | 4,115 | 2,380 | 57.8 % |
| Cassia | 443 | 10,032 | 5,949 | 59.3 % |
| Clark | 13 | 615 | 404 | 65.7 % |
| Clearwater | 210 | 5,213 | 3,191 | 61.2 % |
| Custer | 145 | 2,967 | 1,671 | 56.3 % |
| Elmore | 444 | 9,567 | 5,198 | 54.3 % |
| Franklin | 212 | 5,245 | 3,393 | 64.7 % |
| Fremont | 267 | 6,450 | 4,000 | 62.0 % |
| Gem | 376 | 7,987 | 4,901 | 61.4 % |
| Gooding | 190 | 7,053 | 4,079 | 57.8 % |
| Idaho | 335 | 9,578 | 5,809 | 60.6 % |
| Jefferson | 575 | 9,523 | 6,169 | 64.8 % |
| Jerome | 177 | 8,532 | 4,831 | 56.6 % |
| Kootenai | 1,397 | 54,569 | 29,793 | 54.6 % |
| Latah | 2,214 | 21,682 | 12,384 | 57.1 % |
| Lemhi | 211 | 4,849 | 3,488 | 71.9 % |
| Lewis | 70 | 2,352 | 1,434 | 61.0 % |
| Lincoln | 85 | 2,093 | 1,238 | 59.1 % |
| Madison | 823 | 10,851 | 6,527 | 60.2 % |
| Minidoka | 253 | 9,118 | 5,498 | 60.3 % |
| Nez Perce | 983 | 22,119 | 13,380 | 60.5 % |
| Oneida | 81 | 2,288 | 1,280 | 55.9 % |
| Owyhee | 214 | 4,677 | 2,762 | 59.1 % |
| Payette | 519 | 9,481 | 5,434 | 57.3 % |
| Power | 97 | 3,755 | 2,222 | 59.2 % |
| Shoshone | 116 | 7,931 | 4,138 | 52.2 % |
| Teton | 134 | 3,319 | 1,820 | 54.8 % |
| Twin Falls | 799 | 30,378 | 17,641 | 58.1 % |
| Valley | 289 | 5,920 | 3,268 | 55.2 % |
| Washington | 139 | 5,353 | 3,438 | 64.2 % |
| Total | 36,522 | 661,433 | 386,720 | 58.5 % |
| 1st Cong. Dist. | 19,686 | 358,725 | 209,499 | 58.4 % |
| 2nd Cong. Dist. | 16,836 | 302,708 | 177,221 | 58.5 % |