Me. Stat. tit. 21-A § 1305
This agreement takes effect when states cumulatively possessing a majority of the electoral votes have enacted this agreement in substantially the same form and the enactments by such states have taken effect in each state.
Any member state may withdraw from this agreement, except that a withdrawal occurring 6 months or less before the end of a President's term does not become effective until a President or Vice President has been qualified to serve the next term.
The chief executive of each member state shall promptly notify the chief executive of all other states when this agreement has been enacted and has taken effect in that official's state, when the state has withdrawn from this agreement and when this agreement takes effect generally.
This agreement terminates if the electoral college is abolished.
If any provision of this agreement is held invalid, the remaining provisions are not affected.
21-A M.R.S. § 1305