Voting in Bihar has long been polarized along caste lines, and so it was in 2015

Community-wise vote share in % in 2015 Assembly polls

RJD+ BJP+

RJD+ refers to the alliance of Rashtriya Janata Dal, Janata Dal (United) and Congress. BJP+ refers to Bharatiya Janata Party, Lok Janshakti Party, Rashtriya Lok Samta Party, and Hindustani Awam Morcha.

Source: CSDS Data Unit, via "Post-Mandal Politics in Bihar" by Sanjay Kumar Get the data