Maine constitution
Article IV-2: senate
Section 5

The Senate shall, on said first Wednesday of December, biennially determine who is elected by a plurality of votes to be Senator in each district. All vacancies in the Senate arising from death, resignation, removal from the State or like causes, and also vacancies, if any, which may occur because of the failure of any district to elect by a plurality of votes the Senator to which said district shall be entitled shall be filled by an immediate election in the unrepresented district. The Governor shall issue a proclamation therefore and therein fix the time of such election.