Former US senator George McGovern, the Democrat who lost to president Richard Nixon in 1972 in a historic landslide, has died at the age of 90.
Family spokesman Steve Hildebrand said that Mr McGovern died today at a hospice in Sioux Falls, South Dakota, surrounded by family and friends.
Mr McGovern was a bomber pilot in World War Two who became an early critic of the Vietnam War and a leader of the Democrats' liberal wing.
He was elected to his first of three Senate terms in 1962.
Mr McGovern ran for president three times, also making a try for the nomination in 1968 and 1984.
Despite the 1972 Watergate break-in, Mr Nixon won a second term in one of the biggest landslides in modern history.
"We are blessed to know that our father lived a long, successful and productive life advocating for the hungry, being a progressive voice for millions and fighting for peace. He continued giving speeches, writing and advising all the way up to and past his 90th birthday, which he celebrated this summer," a family statement said.
Mr McGovern said he learned to hate war by waging it. In his disastrous race against Nixon, he promised to end the conflict in Vietnam and cut defence spending by billions of dollars.
He helped create the Food for Peace programme and spent much of his career believing the United States should be more accommodating to the former Soviet Union.
Never a showman, he made his case with a style as plain as the prairies where he grew up, often sounding more like the Methodist minister he had once studied to be than a long-time US senator and three-time candidate for president.
And Mr McGovern never shied from the word "liberal," even as other Democrats blanched at the label and Republicans used it as an epithet.
"I am a liberal and always have been," Mr McGovern said in 2001. "Just not the wild-eyed character the Republicans made me out to be."
Americans voting for president in 1972 were aware of the Watergate break-in, but the most damaging details of Nixon's involvement wouldn't emerge until after election day.
Mr McGovern tried to make a campaign issue out of the bungled attempt to wiretap the offices of the Democratic National Committee, and he called Nixon the most corrupt president in history, but the issue could not eclipse the embarrassing missteps of his own campaign.
Mr McGovern was tortured by the selection of Missouri senator Thomas F Eagleton as the vice presidential nominee, and 18 days later, following the disclosure that Mr Eagleton had undergone electroshock therapy for depression, decided to drop him from the ticket despite having pledged to back him "1,000 %."
It was at once the most memorable and the most damaging line of his campaign, and called "possibly the most single damaging faux pas ever made by a presidential candidate" by the late political writer Theodore H White.
After a hard day's campaigning - Nixon did virtually none - Mr McGovern would complain to those around him that nobody was paying attention. With R Sargent Shriver as his running mate, he went on to carry only Massachusetts and the District of Columbia, winning just 38% of the popular vote.
"Tom and I ran into a little snag back in 1972 that in the light of my much advanced wisdom today, I think was vastly exaggerated," MrMcGovern said at an event with Mr Eagleton in 2005. Noting that Nixon and his running mate, Spiro Agnew, would both ultimately resign, he joked, "If we had run in '74 instead of '72, it would have been a piece of cake."
Mr McGovern's campaign, nevertheless, left a lasting imprint on American politics. Determined not to make the same mistake, presidential nominees have since interviewed and intensely investigated their choices for vice president.
Former president Bill Clinton got his start in politics when he signed on as a campaign worker for Mr McGovern and is among the legion of Democrats who credit him with inspiring them to public service.
"I believe no other presidential candidate ever has had such an enduring impact in defeat," Mr Clinton said in 2006 at the dedication of McGovern's library in Mitchell, South Dakota. "Senator, the fires you lit then still burn in countless hearts."