The 1978 Maine United States Senate election was held on November 7, 1978 to select the U.S. Senator

United States Senate

The United States Senate is the upper house of the bicameral legislature of the United States, and together with the United States House of Representatives comprises the United States Congress. The composition and powers of the Senate are established in Article One of the U.S. Constitution. Each...

 from the state of Maine

Maine

Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...

. Freshman Democratic

Democratic Party (United States)

The Democratic Party is one of two major contemporary political parties in the United States, along with the Republican Party. The party's socially liberal and progressive platform is largely considered center-left in the U.S. political spectrum. The party has the lengthiest record of continuous...

 Senator William Hathaway

William Hathaway

William Dodd Hathaway is an American Democratic Party politician from Maine.He was born in Cambridge, Massachusetts. He served in World War II in the Army Air Corps, where he was shot down while bombing the Ploesti, Romania...

 decided to seek re-election, but was trounced by Congressman William Cohen

William Cohen

William Sebastian Cohen is an author and American politician from the U.S. state of Maine. A Republican, Cohen served as Secretary of Defense under Democratic President Bill Clinton.-Early life and education:...

 in the November general election by a margin of 22.6 points. No incumbent senator has been defeated by such a wide margin since.

Candidates

Democrat William Hathaway

William Hathaway

William Dodd Hathaway is an American Democratic Party politician from Maine.He was born in Cambridge, Massachusetts. He served in World War II in the Army Air Corps, where he was shot down while bombing the Ploesti, Romania...

 faced Republican William Cohen

William Cohen

William Sebastian Cohen is an author and American politician from the U.S. state of Maine. A Republican, Cohen served as Secretary of Defense under Democratic President Bill Clinton.-Early life and education:...

 and several third-party candidates in the November general election.

Republican Party

• William Cohen
  William Cohen
  William Sebastian Cohen is an author and American politician from the U.S. state of Maine. A Republican, Cohen served as Secretary of Defense under Democratic President Bill Clinton.-Early life and education:...
  
   – Representative from Maine's 2nd congressional district
  Maine's 2nd congressional district
  Maine's 2nd congressional district is a congressional district in the U.S. state of Maine. Covering , it comprises nearly 80% of the state. It is the largest district east of the Mississippi River and the 24th-largest overall. The district consists of all of the state north of the Portland and...
  
   (1973–1979)

Election results