| 2020 | Democratic | 9,655,595 | 57.2% | | | Republican | 0 | 0.0% | | | Independent | 7,217,064 | 42.8% | |
| 2018 | Democratic | 4,499,702 | 37.3% | | | Republican | 0 | 0.0% | | | Independent | 7,551,434 | 62.7% | |
| 2016 | Democratic | 4,318,905 | 37.4% | | | Republican | 0 | 0.0% | | | Independent | 7,226,337 | 62.6% | |
| 2012 | Democratic | 7,043,917 | 56.6% | | | Republican | 0 | 0.0% | | | Independent | 5,400,218 | 43.4% | |
| 2010 | Democratic | 3,253,872 | 38.6% | | | Republican | 0 | 0.0% | | | Independent | 5,177,002 | 61.4% | |
| 2008 | Democratic | 3,652,695 | 53.6% | | | Republican | 0 | 0.0% | | | Independent | 3,166,784 | 46.4% | |
| 2006 | Democratic | 3,521,055 | 42.2% | | | Republican | 0 | 0.0% | | | Independent | 4,814,850 | 57.8% | |
| 2004 | Democratic | 3,478,774 | 32.5% | | | Republican | 0 | 0.0% | | | Independent | 7,227,433 | 67.5% | |
| 2002 | Democratic | 1,802,783 | 27.1% | | | Republican | 0 | 0.0% | | | Independent | 4,849,108 | 72.9% | |
| 2000 | Democratic | 3,234,492 | 47.0% | | | Republican | 0 | 0.0% | | | Independent | 3,654,688 | 53.0% | |
| 1998 | Democratic | 1,802,444 | 24.6% | | | Republican | 0 | 0.0% | | | Independent | 5,521,372 | 75.4% | |
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