India, Aug. 5 -- "BJP is itself the reason behind its defeat. It's no longer the party of Atal-Advani-Murli Manohar Joshi. Now they are arrogant and dictatorial, and as a result its core voters are shifting away," says a voter in Bihar, summing up the sentiment after Prashant Kishor's historic victory in Bankipur.

Former election strategist-turned-politician Prashant Kishor's demolition of a long-standing BJP fortress has sparked debate over whether the Jan Suraaj Party (JSP) chief's convincing win in the Kayastha-dominated constituency signals the beginning of a political shift in Bihar-a state long plagued by migration, unemployment and underdevelopment.

A defeat by more than 19,000 votes in a by-election, which conventionally favours...