Maine voters chose electors to represent them in the Electoral College via a popular vote, pitting the Republican Party's nominee, businessman Donald Trump, and running mate Indiana Governor Mike Pence against Democratic Party nominee, former Secretary of State Hillary Clinton, and her running mate Virginia Senator Tim Kaine.

On election day, Clinton carried Maine's two at-large electoral votes with a plurality and won Maine's 1st congressional district, while Trump won Maine's 2nd congressional district, making him the first Republican to do so since George H. W. Bush in 1988[a] and also making him the first Republican to win an electoral vote from a New England state since George W. Bush won New Hampshire in 2000.

Sanders swept all of Maine's counties and also won a large share of the democratic caucus votes in New England.

Ted Cruz, Marco Rubio, Donald Trump, and John Kasich were all on the ballot for the 2016 Maine state Republican caucuses.

The caucuses were held on March 5, 2016, in the following counties in Maine: Cumberland, Franklin, Piscataquis, Somerset, Aroostook, Androscoggin, Sagadahoc, Kennebec, Lincoln, Knox, Hancock, Waldo, Washington, York, Oxford, and Penobscot.

[5][6] On March 13, 2016, it was announced that Jill Stein had won the Maine Green Independent Party caucuses.

The party then sued Dunlap, claiming Maine's ballot access requirements were unconstitutionally unreasonable.

[10] On July 13, Dunlap certified that 5,150 signatures had been validated, surpassing the threshold required to allow their candidates on the ballot.