Vermin means an invasive species. So if the Democrats were to come into power then technically they would be the "vermin".
Fortunately for the Republicans a species can only become Vermin when it has no known natural predators. This unfortunately doesn't bode well for your wishes to have any hope. As the Pre-existing predators or dominant species, The Republicans will eat you alive this November. Because the Democrats are the pathetic dirty invasive pests they have always been and you will be crushed under the feet of voters at the voting booth. Possibly to not mount a return for another 8 to 12 years if ever again.