Adams |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 2074 |
| Edwin J. Alexander | R | 1678 |
Asotin |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 3121 |
| Edwin J. Alexander | R | 1737 |
Benton |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 15261 |
| Edwin J. Alexander | R | 10861 |
Chelan |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 9307 |
| Edwin J. Alexander | R | 6206 |
Clallam |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 8615 |
| Edwin J. Alexander | R | 4466 |
Clark |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 27702 |
| Edwin J. Alexander | R | 13528 |
Columbia |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 1135 |
| Edwin J. Alexander | R | 784 |
Cowlitz |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 15367 |
| Edwin J. Alexander | R | 7383 |
Douglas |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 4011 |
| Edwin J. Alexander | R | 2179 |
Ferry |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 816 |
| Edwin J. Alexander | R | 407 |
Franklin |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 5691 |
| Edwin J. Alexander | R | 2960 |
Garfield |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 887 |
| Edwin J. Alexander | R | 573 |
Grant |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 9428 |
| Edwin J. Alexander | R | 4100 |
Grays Harbor |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 14518 |
| Edwin J. Alexander | R | 6016 |
Island |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 4241 |
| Edwin J. Alexander | R | 3140 |
Jefferson |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 2778 |
| Edwin J. Alexander | R | 1284 |
King |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 262264 |
| Edwin J. Alexander | R | 159892 |
Kitsap |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 26509 |
| Edwin J. Alexander | R | 10212 |
Kittitas |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 4911 |
| Edwin J. Alexander | R | 2959 |
Klickitat |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 2728 |
| Edwin J. Alexander | R | 1679 |
Lewis |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 10378 |
| Edwin J. Alexander | R | 6817 |
Lincoln |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 2710 |
| Edwin J. Alexander | R | 1885 |
Mason |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 5487 |
| Edwin J. Alexander | R | 2578 |
Okanogan |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 5697 |
| Edwin J. Alexander | R | 3178 |
Pacific |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 4116 |
| Edwin J. Alexander | R | 1788 |
Pend Oreille |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 1706 |
| Edwin J. Alexander | R | 808 |
Pierce |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 87306 |
| Edwin J. Alexander | R | 36156 |
San Juan |
| Candidate | Party | Votes |
|---|
| Edwin J. Alexander | R | 945 |
| Robert S. O'Brien | D | 857 |
Skagit |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 13150 |
| Edwin J. Alexander | R | 7905 |
Skamania |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 1386 |
| Edwin J. Alexander | R | 671 |
Snohomish |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 52463 |
| Edwin J. Alexander | R | 27347 |
Spokane |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 64411 |
| Edwin J. Alexander | R | 38592 |
Stevens |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 4083 |
| Edwin J. Alexander | R | 2558 |
Thurston |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 18565 |
| Edwin J. Alexander | R | 10354 |
Wahkiakum |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 960 |
| Edwin J. Alexander | R | 504 |
Walla Walla |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 7822 |
| Edwin J. Alexander | R | 7358 |
Whatcom |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 17707 |
| Edwin J. Alexander | R | 10060 |
Whitman |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 7005 |
| Edwin J. Alexander | R | 5281 |
Yakima |
| Candidate | Party | Votes |
|---|
| Robert S. O'Brien | D | 25236 |
| Edwin J. Alexander | R | 20402 |