Modi was always on the lookout for a powerful Patel leader who could fill the vacuum created by the desertion of Keshubhai Patel. So they both needed each other and have complemented each other.
He derived all his power and following from his closeness to Lalu Prasad. In absence of Lalu's support, he is a non-entity in terms of electoral winnability. And it has been proved through his continuous electoral losses after he deserted Lalu Prasad.
Political observers in Bihar feel that closeness to BJP may not yield any political dividend to Sadhu but will definitely hit BJP's prospects badly.
In fact, it can once again polarize the electorate into anti-Lalu family forces and pro-Lalu family forces.
