Voter Registration Totals as of December 4, 2018
| County |
Constitution |
Democratic |
Libertarian |
Republican |
Unaffiliated |
Total Registered |
| Ada |
638 |
46,365 |
2,984 |
104,596 |
98,027 |
252,610 |
| Adams |
17 |
191 |
14 |
1,750 |
718 |
2,690 |
| Bannock |
143 |
5,255 |
438 |
17,862 |
19,782 |
43,480 |
| Bear Lake |
15 |
117 |
11 |
2,619 |
611 |
3,373 |
| Benewah |
24 |
538 |
27 |
2,484 |
2,146 |
5,219 |
| Bingham |
77 |
1,629 |
79 |
12,561 |
5,481 |
19,827 |
| Blaine |
16 |
3,202 |
119 |
3,401 |
7,085 |
13,823 |
| Boise |
26 |
364 |
44 |
3,021 |
1,512 |
4,967 |
| Bonner |
157 |
2,688 |
248 |
15,227 |
8,198 |
26,518 |
| Bonneville |
181 |
4,160 |
440 |
30,289 |
18,376 |
53,446 |
| Boundary |
30 |
443 |
57 |
4,245 |
1,636 |
6,411 |
| Butte |
5 |
66 |
4 |
1,165 |
288 |
1,528 |
| Camas |
6 |
37 |
6 |
462 |
210 |
721 |
| Canyon |
425 |
9,616 |
831 |
46,319 |
32,489 |
89,680 |
| Caribou |
19 |
108 |
13 |
2,702 |
833 |
3,675 |
| Cassia |
30 |
530 |
43 |
6,880 |
2,199 |
9,682 |
| Clark |
2 |
17 |
2 |
309 |
49 |
379 |
| Clearwater |
13 |
386 |
31 |
2,323 |
1,814 |
4,567 |
| Custer |
4 |
156 |
19 |
2,055 |
671 |
2,905 |
| Elmore |
45 |
1,017 |
93 |
6,095 |
3,424 |
10,674 |
| Franklin |
42 |
173 |
29 |
4,672 |
1,292 |
6,208 |
| Fremont |
30 |
294 |
23 |
5,160 |
1,361 |
6,868 |
| Gem |
55 |
670 |
61 |
6,422 |
2,852 |
10,060 |
| Gooding |
23 |
590 |
34 |
3,907 |
1,887 |
6,441 |
| Idaho |
38 |
582 |
57 |
6,766 |
2,532 |
9,975 |
| Jefferson |
49 |
458 |
62 |
10,337 |
3,156 |
14,062 |
| Jerome |
122 |
681 |
43 |
4,423 |
2,720 |
7,989 |
| Kootenai |
368 |
9,244 |
795 |
45,413 |
28,695 |
84,515 |
| Latah |
86 |
4,621 |
318 |
7,720 |
10,248 |
22,993 |
| Lemhi |
11 |
390 |
31 |
3,319 |
1,256 |
5,007 |
| Lewis |
7 |
174 |
10 |
1,290 |
641 |
2,122 |
| Lincoln |
9 |
175 |
17 |
1,345 |
643 |
2,189 |
| Madison |
93 |
598 |
188 |
13,209 |
4,703 |
18,791 |
| Minidoka |
25 |
597 |
32 |
4,954 |
2,321 |
7,929 |
| Nez Perce |
79 |
2,739 |
142 |
8,968 |
10,363 |
22,291 |
| Oneida |
7 |
100 |
20 |
1,927 |
480 |
2,534 |
| Owyhee |
31 |
430 |
35 |
3,288 |
1,427 |
5,211 |
| Payette |
40 |
948 |
68 |
6,425 |
3,691 |
11,172 |
| Power |
8 |
406 |
12 |
1,761 |
1,276 |
3,463 |
| Shoshone |
24 |
1,379 |
31 |
2,503 |
2,675 |
6,612 |
| Teton |
16 |
1,334 |
65 |
2,525 |
2,634 |
6,574 |
| Twin Falls |
148 |
3,283 |
281 |
20,284 |
12,575 |
36,571 |
| Valley |
16 |
951 |
40 |
3,402 |
2,234 |
6,643 |
| Washington |
12 |
414 |
28 |
3,678 |
1,313 |
5,445 |
| Total |
3,212 |
108,116 |
7,925 |
440,063 |
308,524 |
867,840 |