Definitely lots of folks lining up for the long haul. Hydro Quebec has funded a PAC to push for it being built (they are the primary benefactor). Two large gas fired power plants in Maine are funding a PAC against the project. The utility who owns the ROW is also setting up PAC. If the petition drive makes it on the ballot than all the PACs will try to sway the electorate. The population of Maine is concentrated in the southern most three counties which tend to be liberal and are not impacted by the construction of the lines will most likely decide the vote.
Meanwhile Mass banked on offshore wind but recent federal actions is going to put a several year delay in permitting.