Sonpur is an assembly constituency in Saran district in the Indian state of Bihar.OverviewAs per Delimitation of Parliamentary and Assembly constituencies Order, 2008, No. 122 Sonpur (Vidhan Sabha constituency) is composed of the following: Sonpur and Dighwara C.D blocks.Sonepur (Vidhan Sabha constituency) is part of No. 20 Saran (Lok Sabha constituency). It was earlier part of Chapra (Lok Sabha constituency).Election results1977-2015In 2015 state assembly elections, Dr. Ramanuj Prasad (RJD) defeated Vinay Kumar Singh of BJP. In the 2010 state assembly elections, Vinay Kumar Singh, of BJP won the Sonepur assembly seat defeating his nearest rival Rabri Devi of RJD. Contests in most years were multi cornered but only winners and runners are being mentioned.Ramanuj Prasad of RJD defeated Vinay Kumar Singh of BJP in October 2005 and February 2005. Vinay Kumar Singh of BJP defeated Ramanuj Prasad of RJD in 2000. Raj Kumar Rai of JD defeated Birendra Narayan Singh of Congress in 1995 and 1990. Laloo Prasad of LD defeated Raj Narain Singh of Congress in 1985. Laloo Prasad of Janata Party (Secular – Charan Singh) defeated Jawahar Prasad Singh of Congress in 1980. Ram Sundar Das of JP defeated Rameshwar Prasad Rai, Independent, in 1977.