Howard Dean came to national prominence in the US during his bid to be the Democratic presidential candidate in 2004.
Howard Dean: Colourful, controversial but influential
He drew admiration for the way he used the internet to recruit supporters and raise millions of dollars, something that is now taken for granted.
But he bowed out of that race after his "Iowa scream" - a primal shout of defiance following his defeat in that state's primary that sent shivers down many people's backs, not least his own supporters.
In the years since then, Mr Dean has come to wield considerable political clout as the chairman of the Democratic National Committee (DNC).
He was elected to the post in February 2005, despite considerable opposition from some fellow Democrats.
During his failed presidential bid, Mr Dean portrayed himself as a Washington outsider, a role he continues to relish.
"This is a line I probably shouldn't use in Washington but I will. When I came to the DNC we fired all the Washington consultants because we paid all of them a lot of money to tell us how to lose every four years," he said in August.
For Mr Dean, the foundation of his term as party chairman revolves around what is termed the "50-state strategy" - a root-and-branch overhaul of the Democratic Party's organisation.
This involves hiring local leaders in every state, even rock-solid Republican ones, paying them salaries, and building up a new voter database.
Some party members have argued that funds would have been better used to target states that have a realistic prospect of voting for a Democratic contender, rather than spreading money all around.
But Mr Dean's supporters say his approach has transformed the party.
Mr Dean was born into a wealthy family of investment bankers and enjoyed a privileged life among the East Coast elite with summers in exclusive parts of Long Island.
He got his undergraduate degree at Yale and went on to medical school. He was eligible for the military draft during the Vietnam War, but won a medical deferment for a back problem.
Married with two children, lives in Vermont
Born in 1948 in East Hampton, New York
Graduated from Yale in 1971 and from medical school in 1978
Practised medicine in partnership with physician wife Judith
Elected to Vermont House of Representative in 1982
Vermont governor in 1991, successive re-election wins, stood down in 2002
Elected DNC chairman 2005
He met his wife, Judith Steinberg, at a New York medical college and she later joined him in Vermont where he had moved in 1978 to continue his hospital training. They later ran a medical practice together, and had two children - a daughter and a son.
He says he first became interested in politics when he campaigned for the creation of a lake-front public bicycle path in Burlington.
From there, he became a member of the state House of Representatives from 1982 to 1986 and stood successfully to become Vermont lieutenant-governor, taking up the job in 1987.
He became governor in 1991 on the death of the incumbent Richard Snelling and served 11 years, being re-elected every two years with large majorities, before standing down.
Mr Dean's bid for the presidency was marked by colourful quips and off-the-cuff remarks that forced him at times to backtrack or apologise.
His chairmanship of the party has also involved rows between the national and state parties over the calendar and delegate allocation for the party's nominating convention.
But Mr Dean remains convinced the Democratic Party is on the right path.
"The days of the Democratic Party not showing up in half the states are over. When Democrats show up, talk about our values how we will create jobs and provide healthcare, we can win in any party of the country," he told The Washington Times.
Come November, if Barack Obama secures the presidency and if the Democrats continue or improve on their electoral success in the congressional mid-term elections, Mr Dean will be able to point to a significant political legacy.