U.S. state constitutional amendments banning same-sex unions States that have voted on amendments States that have voted on amendments

| State_ | Date_ | Yes_vote | No_vote | Vote_outcome |
|---|---|---|---|---|
| West: | West: | West: | West: | West: |
| Alaska | 1998 | 68% (152,965) | 32% (71,631) | Yes |
| Hawaii | 1998 | 71% (285,384) | 29% (117,827) | Yes |
| Nevada | 2002 | 67% (337,183) | 33% (164,555) | Yes |
| Montana | 2004 | 67% (295,070) | 33% (148,263) | Yes |
| Oregon | 2004 | 57% (1,028,546) | 43% (787,556) | Yes |
| Utah | 2004 | 66% (593,297) | 34% (307,488) | Yes |
| Arizona | 2006 | 48% (574,332) | 52% (607,769) | No |
| Colorado | 2006 | 56% (865,126) | 44% (674,030) | Yes |
| Idaho | 2006 | 63% (282,301) | 37% (163,408) | Yes |
| Arizona | 2008 | 56% (1,258,355) | 44% (980,753) | Yes |
| California | 2008 | 52% (7,001,084) | 48% (6,401,482) | Yes1 |
| Midwest: | Midwest: | Midwest: | Midwest: | Midwest: |
| Nebraska | 2000 | 70% (450,073) | 30% (189,555) | Yes |