David Ferdinand Durenberger (August 19, 1934 – January 31, 2023) was an American politician and attorney from Minnesota who served as a Republican member of the United States Senate from 1978 to 1995.

He left the Republican Party in 2005 and became a critic of it, endorsing Democratic presidential nominees Hillary Clinton and Joe Biden in 2016 and 2020, respectively.

It had been founded in 1929 by Republican Harold Stassen, later the Governor of Minnesota from 1939 to 1943, and Elmer Ryan, a Democrat who was member of the United States House of Representatives from 1935 to 1941.

[9][10] Durenberger was reelected in 1982 and again in 1988, defeating Mark Dayton and Minnesota Attorney General Skip Humphrey, respectively.

Durenberger voted for the bill establishing Martin Luther King Jr. Day as a federal holiday and the Civil Rights Restoration Act of 1987 (as well as to override Ronald Reagan's veto).

[13][14][15] He voted to confirm Robert Bork and Clarence Thomas to the Supreme Court of the United States.

[16][17] In 1990, the senate voted 96–0 to censure Durenberger for ethics violations related to evading limits on $100,000 in speaking fees and using his condominium in Minneapolis to collect $40,000 in travel reimbursements.

He also said that Democrats are better equipped to handle health care and that President George W. Bush was wrong about the Iraq War.

[25] In 2010, Durenberger endorsed his former chief of staff, Independence-Alliance Party member Tom Horner, for governor.