| 2020 | Democratic | 9,577,807 | 56.0% | | | Republican | 0 | 0.0% | | | Independent | 7,514,317 | 44.0% | |
| 2016 | Democratic | 4,026,710 | 29.9% | | | Republican | 0 | 0.0% | | | Independent | 9,427,714 | 70.1% | |
| 2012 | Democratic | 6,460,264 | 52.0% | | | Republican | 0 | 0.0% | | | Independent | 5,974,243 | 48.0% | |
| 2008 | Democratic | 6,015,944 | 47.4% | | | Republican | 0 | 0.0% | | | Independent | 6,680,485 | 52.6% | |
| 2006 | Democratic | 2,962,546 | 35.8% | | | Republican | 0 | 0.0% | | | Independent | 5,305,852 | 64.2% | |
| 2004 | Democratic | 1,840,002 | 16.4% | | | Republican | 0 | 0.0% | | | Independent | 9,411,198 | 83.6% | |
| 2002 | Democratic | 3,139,478 | 44.7% | | | Republican | 0 | 0.0% | | | Independent | 3,882,118 | 55.3% | |
| 2000 | Democratic | 3,294,310 | 32.8% | | | Republican | 0 | 0.0% | | | Independent | 6,743,986 | 67.2% | |
| 1998 | Democratic | 3,325,129 | 42.6% | | | Republican | 0 | 0.0% | | | Independent | 4,486,989 | 57.4% | |
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