RJD in its decade plus of rule over Bihar managed to shrink the economy(in a 4-5TFR state ) and this was coincidental with post liberalisation boom across India. Its what you'd get if a legit gang of criminals began to run government(and I'm not being hyperbolic, middle class literally abandoned Bihar because of skyrocketing kidnapping cases) Current gdp/capita is 600$ compared to national 2,400.

Many reasons