Once again, it is Narendra Modi who has contributed a new stress-point to the relationship between his party and Nitish Kumar, who together form the government in Bihar. Over the weekend, Mr Modi said at a rally in Gujarat that "festering caste politics" in Bihar is the main reason for what he calls the state's backwardness. "Bihar, at one point of time, was a political and spiritual leader of the country, but it slipped into socio-economical backwardness ever since casteist leadership took centrestage," he said. Mr Kumar retorted today that he doesn't need Mr Modi to preach to him. "He should first look at what he has done in Gujarat," he said, in an indirect reference to Gujarat's communal riots in 2002, which remain a major obstacle between Mr Modi and his ambitions for a national-level role with his party, the BJP.