Nitish Kumar, 75, is likely to file his nomination for the Rajya Sabha as a Janata Dal (United) nominee on Thursday, people aware of the matter said, triggering speculation over who will replace him as the Bihar chief minister months after the National Democratic Alliance (NDA) swept back to power in the state.. Bihar chief minister Nitish Kumar has been the central figure in Bihar’s politics for nearly two decades. (HT PHOTO). Thursday is the last day for filing nominations for the Rajya Sabha elections. Kumar’s son, Nishant, who is set to join the JD(U) on Thursday, is likely to be inducted as a deputy chief minister.. The JD(U) has made no formal announcement about the likely developments. The party can win two Rajya Sabha seats on its own and help an NDA candidate secure another. The JD(U) has not named any candidates.. On Wednesday, Union minister Giriraj Singh refuted the speculation about Kumar’s Rajya Sabha nomination, saying such jokes are common on Holi.. Kumar has been the central figure in Bihar’s politics for nearly two decades. His possible shift to Delhi could reshape the ruling NDA in the state.. The people cited above said Kumar is expected to vacate the chief minister’s post only after the nomination process, election, and oath as a member of Parliament are completed. The Bharatiya Janata Party (BJP) is widely expected to get the chief minister’s post if Kumar steps down. The BJP has long been the dominant partner in the alliance in terms of organisational strength and electoral performance, even though the top post in Bihar has remained with Kumar.. BJP leaders are believed to have begun internal discussions and political assessments in anticipation of a post-Kumar scenario. The BJP leadership is expected to balance multiple factors while choosing Kumar’s successor. The decision will not only be about seniority but also about caste representation, coalition stability, and the broader political message the party wants to send.. Caste dynamics continue to play a decisive role in Bihar’s politics, and any leadership change will take that into account. Extremely Backward Classes (EBC) are among the most influential social groups in the state. Over the years, the EBCs have largely been seen as supporters of the NDA. Political strategists believe that the next chief minister will come from a social background that reassures this important voter base and helps maintain the coalition’s social cohesion.. Women voters are another important factor. In the 2025 election, women’s participation increased significantly, and welfare programmes targeting them were credited with boosting support for the NDA. Networks of women associated with self-help groups, popularly referred to as “Jeevika didis”, emerged as a strong pillar of the ruling alliance’s electoral support.. The BJP is expected to factor in both caste arithmetic and expectations of women voters while picking its chief ministerial candidate. It may lead th