Can Maine Dems gerrymander its congressional districts so both voted for Biden without sacrificing either seat?
Sure, by moving Lewiston into district 1 and moving some coastal areas north/east of Portland into district 2. This would make both districts D-leaning.
One the rudimentary rules of partisan gerrymandering is that you usually need at a minimum 3 districts to make it really work.
With two districts you can only either:
A). draw two districts that both closely matches the state at-large's partisan lean (and hence the map would not be gerrymandered by most partisan metrics)
B). pack the Ds into one district and the Rs into the other, which can be done to varying degrees. This on net will also result in no overall statewide seat or vote bias because any excess votes for one party in one district must be balanced by a specific amount of excess votes for the other party in the second district such that the sum matches the statewide margin. The overall combined competitiveness of the two districts on average would not be much different from scenario A, so no gerrymandering here either.
Scenario A can easily turn into a dummymander if Maine trends R in the future or with a R favorable midterm wave. Also, Maine's current congressional map is already a case of scenario B.
