The Bihar elections are almost certainly going to be Modi’s Waterloo, after which his fortunes are going to rapidly decline. Let me explain.
In most of India, including Bihar, most people vote in elections on caste and religious lines. The exception is when there is a wave, which cuts through these lines.
The BJP had won the May, 2014 Lok Sabha elections on a Modi wave. This wave was due to three main reasons :
1. Modi’s magic slogan of ‘vikas’ (development ) which was perceived as creation of millions of jobs. The Indian youth, whose voting age was reduced from 21 to 18 in 1988, and who are facing the dreadful future of unemployment (10 million youth enter into the job market in India every year, but only half a million jobs are created in the organized sector of the economy), voted en masse for Modi, cutting through caste and religious lines, in the belief that now they will all get jobs.
2.In India unfortunately, the communal virus is still deeply entrenched in society. Most Hindus are communal, and so are most Muslims. Modi was perceived as a ‘ Muslim basher ‘, who had put Muslims in their place in Gujrat in 2002. Many Hindus believe that there has been too much ‘ Muslim appeasement ‘, and so voted for Modi to put Muslims in their place on an all India basis.
3.People were simply disgusted with Congress and the UPA under whose rule scam followed scam regularly
Now the Modi wave has largely dissipated, except among the hardcore, mainly upper caste Hindu fundamentalists.
There are no jobs despite the victory of the BJP. Jobs cannot be created by slogans. They are created when the economy is rapidly expanding, but the Indian economy is practically stagnant. So the youth who were expecting jobs have realized they were befooled and taken for a ride..
The hope that foreign investments will come into India and create jobs has proved to be illusory. In fact Jim Rogers, a leading American investor has withdrawn his investments in India, as widely reported, saying that one cannot invest in mere hope. Who will invest or set up factories in India in most parts of whichthere is lack of infrastructure, massive corruption and corruption ( despite Modi’s tall claim ‘ Na khaoonga na kanendoonga ‘ ).
On the other hand, prices of essential foodstuffs like dal and onions have gone through the roof. This means that the real incomes of most people in India have gone down drastically.
No doubt the communal card is still sought to be played as in incidents in Dadri, etc and the beef ban politics,, but it is not having much effect. Food and jobs are more important to people than religion or talk of Digital India and visits to foreign countries.
So voting in the Bihar elections is following the traditional pattern of caste and religion, and we can therefore forecast the results with almost mathematical precision.
Here are the caste demographics of Bihar which I got from the net :
OBC/EBC 51% ( Yadavs -14%, Kurmis- 4%,( EBCs – 30% -includes
kushwahas – 6% Koeris -8%, Teli-3.2%))
Mahadalits* + Dalits(SCs) 16%
Forward caste 15% (Bhumihar -3%, Brahmin-5%, Rajputs- 6%, Kayasth- 1%)
Adivasis(STs) 1.3% 
Others 0.4% (include Christians,Sikhs,Jains)
As per, 2011 Census of India , Scheduled Castes constitute 16% of Bihar’s 104 million population. The census identified 21 of 23 Dalit sub-castes as Mahadalits. Mahadalit community consists of the following sub castes – Bantar, Bauri, Bhogta, Bhuiya, Chaupal, Dabgar, Dom (Dhangad), Ghasi, Halalkhor, Hari (Mehtar, Bhangi), Kanjar, Kurariar, Lalbegi, Musahar, Nat, Pan (Swasi), Rajwar, Turi, Dhobi, Pasi, Chamar and Paswan (Dusadh). Paswan caste was initially left out of the Mahadalit category. Adivasis (Scheduled Tribes) constitute around 1.3% of Bihar population. Tribals include Gond, Santhal and Tharu communities in Bihar. Extremely Backward Class (EBCs) are also sometimes referred to as Most Backward Class(MBCs). There are 130-odd EBC castes in Bihar.
Yadavs and Kurmis constituting 19% and Muslims about 17% will solidly vote for the Lalu-Nitish alliance, which makes it 36%. Muslims will vote for it (despite Owaisi, who is regarded as a BJP vote splitter by Muslims, and who will therefore not be misled by him) because Muslims are feeling very insecure after love jihad, ghar wapasi, speeches of Adityanath, Sadhvi Niranjan Jyoti ( calling them haramzadas) and incidents like in Muzaffarnagar, Ballabhgarh, and the latest one at Dadri. So they will solidly vote for the Nitish Lalu alliance.
A section of the other backward castes, say 8-10%, will also vote for the alliance, as Lalu has successfully described it as a fight between the backwards and the forward castes.
Thus the tally of the Nitish-Lalu alliance comes to about 45% votes, which represents a sweep ( BJP got a majority in the Lok Sabha with only 31% votes )
As regards, the NDA, its support is from the upper castes, and a section of EBCs( also called MBCs ) and a section of dalits, because of Paswan, Manjhi and Upendra Kushwaha.
The upper castes in Bihar, as can be seen from the above chart, are altogether only 15%. Paswan does not have the support of all the dalits ( who are divided into a large number of sub castes) in Bihar, unlike Mayawati who has the support of almost all the dalits in U.P. So he may get the NDA about 6-7% votes. Manjhi may get 7-8% MBC votes, and Kushwaha may get 3%votes.
Thus the total tally of NDA votes is 15+7+8+3=33%. These figures show that there is clearly going to be a sweep in favour of the Mahagathbandhan in Bihar. In the Indian system of democracy, seats in elections depend not on percentage share of votes but on being first past the post. With 31% votes the BJP got an absolute majority in the Lok Sabha. Getting 45% votes means a massive victory.