California Primary Election Tuesday, June 2, 2026
Unofficial Election Results
U.S. House of Representatives District 10 - Contra Costa County Results
Unofficial Election Results
Results will be certified by July 10, 2026.
( 652 of 652 ) precincts partially
reporting as of June 5, 2026, 4:00 p.m. 
Visit the County Reporting Status page to determine when a county has submitted its latest report.
Vote-by-mail, provisional, and other ballots will continue to be processed and counted after Election Night.
Election results will change throughout the ballot counting canvass period as vote-by-mail ballots, provisional ballots (including conditional voter registration provisional ballots), and other ballots are tallied.
| Candidate | County Votes | County % | District Votes | District % | |
|---|---|---|---|---|---|
| Mark DeSaulnier (Party Preference: DEM) | 100,711 | 60.0% | 110,129 | 59.5% | |
| Joshua Hamilton (Party Preference: DEM) | 5,597 | 3.3% | 6,919 | 3.7% | |
| Mitchell Maisler (Party Preference: DEM) | 4,801 | 2.9% | 6,128 | 3.3% | |
| Bob Rowland (Party Preference: DEM) | 2,845 | 1.7% | 3,151 | 1.7% | |
| Jeff Frese (Party Preference: REP) | 22,630 | 13.5% | 24,617 | 13.3% | |
| Angela Griffiths (Party Preference: REP) | 11,129 | 6.6% | 12,392 | 6.7% | |
| Katherine Piccinini (Party Preference: REP) | 20,016 | 11.9% | 21,620 | 11.7% | |
