He said that after 10 years in power, Chief Minister Nitish Kumar had "lost his USP" for which he was known.
"People are listening to him but they do not respond. There is no fire now in Nitish for which he was known," Rudy, the minister of state for skill development and entrepreneurship (independent charge), told IANS in an interview at his official residence here.
But he agreed that RJD chief Lalu Prasad Yadav had been successful in keeping intact his support base in Bihar.
"Nitish Kumar is trying to make 'Bihari pride' an issue but the very fact is that the day when he decided to shake hands with Lalu Yadav, his 'Bihari pride' had come to an end."
Rudy, who hails from Bihar, said Nitish's Bihari pride at one time was based on opposing Yadav. "But he ultimately shook hands with Yadav. Now he is linked with Lalu Pride."
Rudy, who is also the minister of state for parliamentary affairs and was a key strategist for the BJP in the Maharashtra assembly polls, also claimed that Lalu Yadav's supporters would never accept Nitish as their leader.
"Yadavs of Bihar feel that how can Nitish be a leader when the vote bank is with them? They say that Nitish, who enjoyed power with the BJP, has come to them to enjoy power again," he said.
He, however, refused to accept that the caste combination of the state was in favour of the JD(U)-RJD-Congress combine.
"You can't say there is any alliance against us in Bihar. Ram Vilas Paswan, Upendra Kushwaha, Jeetan Ram Manjhi, Narendra Singh, all are out of their alliance. Who is there except Nitish and Lalu?" he said, adding that even the National Congress Party and Samajwadi Party had walked out.
Rudy, who is part of Prime Minister Narendra Modi's core team, however claimed that there was no confusion in Delhi over the leadership issue.
"If anybody in Delhi is in confusion over who is going to be the chief minister, it means something is wrong with him," Rudy replied when asked about who would be the chief minister of the party if BJP took power.
"Everything has been decided and it is a part of our strategy. We all know what is going to be happen but I can't disclose it at this moment," he added. He said there was no infighting over the issue.
Rudy also denied that any pressure was put on the on Samajwadi Party to part ways with the Janata Parivar.
"Those who are guilty expect help from the government. But our government is in no mood to oblige anybody. The law will take its own course," he said.
He was reacting to a question over rumours that the central government had offered to help Samajwadi Party leader Mulayam Singh Yadav in resolving the CBI case against him in case he quit the Janata tie-up.
But he refused to confirm an alleged secret meeting between Samajwadi Party general secretary Ram Gopal Yadav and BJP president Amit Shah. "I have no idea about the reports of this meeting. I am really unaware of it."
Last week, the Samajwadi Party walked out of the coalition of regional parties for Bihar, accusing the JD-U-RJD alliance of not consulting it on seat distribution and giving them just five seats to contest.