Mohammed Shahabuddin represents everything that Bihar was supposed to put behind it under Chief Minister Nitish Kumar. The Rashtriya Janata Dal leader, who tends to be described as a strongman, don and baahubali, walked out of the Bhagalpur jail on Saturday after 11 years behind bars. And Shahabuddin immediately began questioning Kumar's legitimacy.

"Nitish Kumar is a leader born out of circumstances," he told reporters outside the jail, after being granted bail by the Patna High Court in an attempted murder case. "Nitish Kumar can be an alliance chief minister, but he is not my leader. Lalu Prasad has been my leader for 27 years, and as long as he is alive, he will continue to be my leader."

Once he was done talking to the press – doing everything from questioning Kumar's much-vaunted prohibition law to insisting that he is now a "free man" (albeit only out on bail) – Shahabuddin was whisked off to his home constituency of Siwan in a cavalcade that the Times of India said included 400 SUVs. On the way, as if to drive home the real impact of the criminal-politician's release, dozens of the vehicles in his convoy simply drove past toll booths without paying.

You couldn't ask for a more perfect warning for this Nitish Kumar government, built on a grand alliance between his Janata Dal (United) and Lalu Prasad Yadav's Rashtriya Janata Dal, with the Congress as a junior partner. When Shahabuddin was put in jail in 2005, Kumar, then in an alliance with the Bharatiya Janata Party, took credit for ending his reign of terror and bringing law and order to a state known otherwise for "jungle raj".

The release of the strongman, who was given a life sentence in 2007 in an abduction case and has made an entire career out of using criminal activity as a shortcut to political gains, offers up the best example yet of how Kumar's alliance with Lalu Prasad Yadav rests on shaky ground. As if to underscore this, another RJD leader also took the opportunity to remind the public that Kumar was not their choice.

Leader of circumstance

"The members of the grand alliance took a call on Nitish Kumar as their chief ministerial candidate," said Raghuvansh Prasad Singh, a former Member of Parliament. "The leaders had already decided. So, we had to agree."

How Shahabuddin acts, and is treated by authorities, from here on will be a key test of Nitish Kumar's government.

Although Bihar under Lalu Prasad Yadav demonstrated progress on the welfare front, his reign became infamous as a time when strongmen-politicians could do as they wished. Shahabuddin was the poster-boy of this jungle raj era, with so many cases against him that Bihar Police labelled him a Type A history-sheeter: "a hardened criminal with a history of crime," who is beyond reform.

When Bihar's grand alliance came together, posting a surprisingly large victory over the BJP last year, there were fears that any government that included the RJD would bring with it a return of the politician-criminals too. Kumar has made a concerted effort to dispel this image and insist that he and not Lalu Yadav – who is barred from contesting elections because of a criminal conviction – calls the shots.

National ambitions

The sight of Shahabuddin not only getting bail because of a suspiciously delayed trial and walking out, but also openly questioning the legitimacy of the chief minister and the efficacy of the prohibition law that Kumar hopes will give him a national platform sends multiple messages that the JD(U) will have to counter. The family of a journalist who was allegedly murdered for reporting on Shahabuddin has already asked the state government for protection, concerned that the RJD's men will once again run riot over Siwan.

Nitish Kumar isn't simply worried about his alliance partner attempting to take the reins of government. Kumar also sees himself as a likely prime ministerial candidate in 2019, if anti-BJP forces decide to come together. The likelihood of earning a bad image because of fresh lawlessness in his own state, or simply getting embroiled in petty intra-alliance spats, would endanger this project.

"Mere liye in sab baton ka koi mahatva nahin hai," Kumar said, when asked about Shahabuddin's comments. "All of this talk is not important to me." But, considering the potential the strongman's release says about the nature of Bihar's grand alliance, you can be sure that Kumar is paying close attention.