| Democratic share of major party registration | 0.743* (0.096) |
| Democratic share of major party campaign contributions | 0.349* (0.046) |
| Dummy variable for Democratic incumbent | −0.007 (0.028) |
| Dummy variable for Republican incumbent | 0.046 (0.031) |
| Observations | 212 |
| R2 | 0.822 |
| Root Mean Squared Error | 0.103 |