Lalu Prasad Yadav's conviction in the 17-year-old fodder scam case not only brings major changes for his Rashtriya Janata Dal (RJD), but also signals the reworking of political arithmetic in Bihar and national politics ahead of polls due in May. The 66-year-old Bihar politician has been jailed and stands disqualified as a Member of Parliament. More significantly for his party, he will not be able to contest next year's national election, and even the one after that.