SEATTLE -- Former state Sen. Martin J. Durkan Sr., a longtime political powerhouse and patriarch of a leading family in Washington state law, politics and influence, is dead at age 81.

Durkan, a Democrat who was conservative on social issues but liberal on environmental and economic matters, died Sunday at Maui Memorial Medical Center in Hawaii, where he and his wife had a vacation home, relatives said, adding that he had been in failing health for some time.

Born in Great Falls, Mont., the son of a state legislator and school teacher, Durkan earned a bachelor's degree at Gonzaga University in Spokane, served with the Navy during World War II and earned a law degree at the University of Washington.

After a two-year term in the state House, he spent 18 years in the state Senate starting in 1958 and gained power as chairman of the budget-writing Senate Ways and Means Committee in the late 1960s.

He helped to write some of the early state legislation on oil spills and sponsored the bill that established the state Ecology Department.

Durkan voted against the Equal Rights Amendment, but on labor and economic issues was known for caring about the disadvantaged and forgotten. He pushed farm worker housing although his urban Seattle-area was far from agricultural areas and the effort brought him no votes.

Durkan ran for governor in 1968 and 1972, but lost both times in the Democratic primary and met the same fate when he ran for Congress in 1977.

Durkan's children have extended the family's influence in numerous sectors of public life:

Jenny Durkan is arguing the Democrats' case in a lawsuit by Republicans challenging the contested gubernatorial election.

Martin J. Durkan Jr. is a development-oriented lobbyist who supported Republican Dino Rossi for governor.

Kathleen Durkan is a former NBC News foreign correspondent and campaign consultant.

Ryan Durkan is a highly regarded land use lawyer. She has worked for the University of Washington and on construction of the Washington State Convention and Trade Center.

Other survivors include his wife, Lolly, and six grandchildren. Memorial services were pending.