WASHINGTON, D.C.: Former Maine Senator and Carter Secretary of State Edmund Muskie died from a heart attack early Tuesday at Georgetown University Hospital. Muskie suffered the attack a few days after undergoing surgery for a clogged artery in his leg. He came to national prominence as Democratic presidential nominee Hubert Humphrey's running mate in 1968. They lost to Nixon and Spiro Agnew. Muskie was the odds-on favorite to win the Democratic presidential nomination in 1972, but he lost to Senator George McGovern of South Dakota. His angry and emotional breakdown in New Hampshire, railing against a story critical of his wife, may have cost him the nomination. As a Senator from 1959 to 1980, Muskie pushed for laws to protect the environment, earning him the nickname "Mr. Clean". After a brief stint as President Carter's Secretary of State in 1980, Muskie retired from public life to join the law firm of Chadbourne and Parke. he would have been 82 on Thursday.