Under his leadership, the Congress not only bagged 53 of the 60 Assembly seats but also won both the Lok Sabha seats from the State this time. Mithi had earlier caused a vertical split in the ruling Arunachal Congress Legislature Party and formed Arunachal Congress (M), after he was dropped from the Cabinet by the then Chief Minister Apang, and voted out. He replaced his predecessor in the top office in January.

Mithi merged his faction of Arunachal Congress into the Congress in April and made the ``mis-governance'' of Apang, who ruled the State for 19 years, the main poll issue and brought off a big success for the Congress.

Born on January 1, 1952 at Roing in Dibang valley district, Mithi was educated at Rama Krishna Mission Schoolat Narendrapur near Calcutta and later at Jabalpur Agriculture University.

He took active part in flood relief work in West Bengal during 1972 and undertook various social activities in Dibang valley sponsored by the government and other organisations.

He was elected to the Assembly for the first time in a by-election in 1983 when Arunachal Pradesh was a Union Territory, and became the deputy minister of forest in 1985 which was followed by his elevation to the cabinet rank in 1987.

After Arunachal Pradesh got Statehood, Mithi was elected to the Assembly in March 1990 and held the portfolios of forest (1990-91), youth affairs and sports (November 1991-August 1992) and health and family welfare (April 1994-March 1995).

After being elected to the second Assembly of the State in March 1995, he became minister for animal husbandry and veterinary and then held the home portfolio.