Gov Lepage allegedly "blackmailed" a Democrat in his state (Maine) by threatening to withhold government funds from a charter school unless the school board denied a prominent Democrat a seat on their board.

http://www.pressherald.com/2015/06/24/house-speaker-eves-fired-from-school-for-at-risk-youth-accuses-lepage-of-blackmailing-school/

Is there any precedent that would suggest (either way) that this is "blackmail", or "extortion", which is the word I think his critics are searching for?