| President Democratic | 100.% ( 452 of 452 ) precincts reporting as of Mar 4, 2008, at 9:49 a.m. County Returns Other Contests | | Sonoma County Results | |
| |
| | Joe Biden (Dem) | 365 | 0.4 % |   | 17,748 | 0.3 % |   |
| | Dennis Kucinich (Dem) | 1,006 | 1.1 % |   | 23,077 | 0.5 % |   |
| | Barack Obama (Dem) | 44,020 | 47.7 % |   | 2,093,318 | 42.9 % |   |
| | Bill Richardson (Dem) | 326 | 0.3 % |   | 19,367 | 0.4 % |   |
| | Hillary Clinton (Dem) | 40,709 | 44.1 % |   | 2,524,799 | 51.8 % |   |
| | Chris Dodd (Dem) | 87 | 0.0 % |   | 7,807 | 0.1 % |   |
| | John Edwards (Dem) | 5,767 | 6.3 % |   | 188,634 | 3.9 % |   |
| | Mike Gravel (Dem) | 130 | 0.1 % |   | 7,870 | 0.1 % |   |
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