After the elections to the Second Legislative Assembly (1969-1974), the
Naga Nationalist Organisation won 22 of the total 40 seats for which elections were conducted, 12 seats from Tuensang Area were nominated from the region. Eventually, the 12 nominated members as well as eight Independent members lent support to the NNO on 12 February raising the strength of the NNO to 41. Thereby, Sema who was elected the leader of the NNO legislative party was sworn in as the third Chief Minister of Nagaland He lost his seat to
Rano M. Shaiza in 1977. In the 1980s he was the leader of the
Congress (I). In 1986 he became Chief Minister for brief period. == Later political career ==