Nitish Kumar has decided to back Ram Nath Kovind for President.

Highlights Nitish Kumar's party breaks with opposition on President nominee

Bihar Chief Minister will support BJP's Ram Nath Kovind

His allies Congress and Lalu Yadav want opposition to field candidate

Chief Minister of Bihar Nitish Kumar phoned Sonia Gandhi, the Congress boss, in April to suggest a corralling of opposition parties over the election of the President of India . Mr Kumar pitched the idea of a united opposition candidate as a test run for a Maha-Gathbandhan or Grand Alliance for the general election in 2019. Mr Kumar phoned Mrs Gandhi again three days ago - this time to convey that he would, in fact, side with the BJP - and not the opposition - on its choice for President. A formal announcement was made this evening by Mr Kumar's party that it will support BJP nominee Ram Nath Kovind, a Dalit who was Governor of Bihar till yesterday.Mr Kumar's party also said it will not attend the meeting of opposition leaders on Thursday that is to be chaired by Mrs Gandhi, though senior leader Sharad Yadav claimed "Our Maha-Gathbandhan is intact and we will continue opposing the BJP."However, the Grand Alliance has whittled down quickly since Monday, when the BJP made the big reveal on Mr Kovind as its choice for President. Several leaders - like Mayawati - have said they cannot object to a Dalit for the highest office in the country.Mr Kumar has told his party apart from the not insignificant caste factor - the Mahadalits are a major support group - he won't be seen as blocking a candidate who was Governor of his state, and who, according to the Chief Minister's public declaration, played by every rule while in office with a neutrality not commonly attributed to Governors appointed by the BJP.When asked about how the BJP won Mr Kumar's support for its candidate, Bhupender Yadav, senior BJP leader from Bihar, was circumspect, stating only "This is a win for democracy."The opposition's meeting on Thursday in Delhi brings together parties that had agreed in principle to taking on the BJP. Mr Kumar is just one part of that agreement's unraveling. Sources say that Sharad Pawar's NCP, privately inclined to assist the BJP, will come through for the centre. The Samajwadi Party has said it will take a call after hearing others out, but its former chief Mulayam Singh Yadav has indicated he favours Mr Kovind.So Prime Minister Narendra Modi and his top aide and BJP chief Amit Shah have scored two big points with Mr Kovind's candidature: fracturing the opposition with immediate effect, and consolidating their outreach to Dalits and lower castes.Sources say that the Bihar Chief Minister's decision is based not just on caste calculations, but on his assessment of the PM's huge approval ratings as the next general election nears. The immense support for the PM's abrupt demonetisation move was reflected in the scale of the BJP's score when it won the political prize of Uttar Pradesh in March. Months before that, while other opposition leaders railed against the notes ban, Mr Kumar correctly gauged that the poor were backing it, and spoke openly in favour of the reform. That support was returned in January by PM Modi, when on a trip to Patna, he publicly praised Mr Kumar's much-criticized alcohol ban in Bihar and said its goal and implementation were to be admired.Mr Kumar co-governs Bihar with Mrs Gandhi's Congress party and Lalu Yadav, whose children, two of whom are ministers, have been named in corruption cases in the last few weeks. The charges of the Yadavs freely acquiring a vast real estate portfolio through proxy-owned firms make Mr Kumar vulnerable - Tejashwi Yadav, who is among the Yadav family members being investigated, is Bihar's Deputy Chief Minister.The partnership between Mr Kumar and Lalu has always been fraught; as Lalu moves to defend his children, the Chief Minister is likely to be measuring the possibility of truncated ties. In that case, a renewed friendship with the BJP could give Mr Kumar more leverage over Lalu , his often-garrulous ally.

After the PM's spectacular show of strength in Uttar Pradesh, the opposition publicly conceded that unless it united against him, it stood no chance of preventing a second term for Mr Modi. Mr Kumar has some experience in this. In 2015, he wiped out years of hostility with Lalu to form an alliance. The Congress became their third partner. Despite an extensive campaign by PM Modi across Bihar, the combination of voters that the three parties provided was unbeatable.Mr Kumar has repeatedly denied recent allegations - including from Lalu's party and the Congress - that he is approaching a union with the BJP. In 2013, it was over the BJP's choosing Mr Modi as its presumptive Prime Minister that Mr Kumar ended his nearly two-decade long alliance with the party. That separation came with Mr Kumar taking a hardline position against Mr Modi, who, he suggested, could not escape the taint of the 2002 riots in Gujarat which took place while Mr Modi was Chief Minister. Mr Kumar's split from the BJP backfired. His decision now to back the BJP against his own allies for the President is an attempt to, at the very least, hedge his bets as the next general election nears.