Nitish Kumar committed the mistake of overlooking the fact that he had actually emerged as an alternative for all anti-Lalu forces including the forward and non-Yadav backward castes who were largely BJP supporters.
As he always planned to make inroads into the crucial Muslim votebank that accounted for 16 percent of the entire population, Nitish tried to keep Narendra Modi at an arm's length in Bihar throughout his alliance with the saffron outfit. He did not allow Modi to campaign in Bihar as long as he was part of NDA alliance.
The reason behind his stiff opposition to Narendra Modi's campaign in Bihar was not just his lust for Muslim votes. He also considered Modi a threat to his support base of non-Yadav backwards. Since Narendra Modi also belongs to the OBC community, Nitish always considered him a threat.
His victory in 2010 assembly elections made him a little more ambitious and he started considering himself a serious contender for PM post if NDA were to win a majority in Lok Sabha elections. His calculation was that the BJP will never get a majority on its own and alliance partners will never accept Narenda Modi as the PM candidate given his negative image among the Muslim community.
