What became a controversial issue in Bihar following the 1977 elections?

Reservation for 'other backward classes'

In an indirect manner, the issue of welfare of the backward castes also began to dominate politics since 1977. The results of 1977 elections were at least partly due to a shift among the backward castes of north India. Following the Lok Sabha elections, many states also held Assembly elections in 1977. Again, the northern States elected non-Congress governments in which the leaders of the backward castes played an important role. The issue of reservations for ‘other backward classes’ became very controversial in Bihar and following this, the Mandal Commission was appointed by the Janata Party government at the centre.