Here's some information about "the longest-serving governor in Vermont's history (five terms):"
http://www.nationmaster.com/encyclopedia/Howard-DeanVermont political career
In 1980, Dean spearheaded a (successful) grassroots campaign to stop a condominium development on Lake Champlain, instead favoring the construction of a bicycle trail. The effort succeeded, and helped launch his political career. That same year, he was also a volunteer for Jimmy Carter's re-election campaign. In 1982, he was elected to the Vermont House of Representatives, where he remained until being elected lieutenant governor in 1986. Both were part-time positions which enabled him to continue practicing medicine.
On August 14, 1991, Dean was examining a patient when he received word that then-Governor Richard A. Snelling had died of a heart attack while cleaning his swimming pool. Dean assumed the office, which he called the "greatest job in Vermont." He was subsequently elected to five two-year terms in his own right, making him the longest-serving governor in Vermont's history. From 1994 to 1995, Dean was the chairman of the National Governors Association.
Dean was faced with an economic recession and a $60 million dollar budget deficit. He bucked many in his own party to immediately push for a balanced budget (Vermont is the only state whose constitution does not require one), an act which marked the beginning of a record of fiscal restraint; during his tenure as governor, the state paid off much of its debt, balanced its budget eleven times, raised its bond rating, and lowered income taxes twice.
Dean also focused on health care issues, most notably through the "Dr. Dynasaur" program, which ensures near-universal health coverage for children and pregnant women in the state; the uninsured rate in Vermont dropped from 12.7% to 9.6% under his watch. Child abuse and teen pregnancy rates were cut roughly in half.
By far the most controversial decision of his career, and the first to draw serious national attention, came in 2000, when the Vermont Supreme Court ruled that the state's marriage laws unconstitutionally excluded same-sex couples and ordered that the state legislature either to allow gays and lesbians to marry or create a parallel status. Facing calls to amend the state constitution to prohibit either option, Dean chose to support the latter one, and signed the nation's first civil unions legislation into law, spurring a short-lived "Take Back Vermont" movement which helped Republicans gain control of the State House.
Dean would receive some flak during his 2004 presidential campaign for another decision related to the civil unions. Shortly before leaving office, he had all his Vermont papers sealed for at least the next decade, a timeframe far longer than most outgoing governors use. He claimed he was protecting the privacy of many gay supporters who sent him letters about the issue. On the campaign trail, he demanded Vice President Dick Cheney release his energy committee papers. Some accused Dean of hypocrisy.
As governor, Dean was endorsed by the National Rifle Association several times, furthering his moderate image.
Elections as Governor of Vermont
Year Democratic Percent Republican Percent Other (>5%) Percent Other (<5%) Percent
1992 Howard Dean 74.73% John McClaughry 23.04% N/A 0% Scattering 3%
1994 Howard Dean 68.6% David F. Kelley 19% Thomas J. Morse (Independent) 7% Scattering 5.4%
1996 Howard Dean 70.5% John L. Gropper 22.4% N/A 0% Scattering 7.1%
1998 Howard Dean 55.6% Ruth Dwyer 41.1% N/A 0% Scattering 3.3%
2000 Howard Dean 50.4% Ruth Dwyer 37.9% Anthony Pollina (Progressive) 9.5% Scattering 2.2%
Source: Vermont Secretary of State