Let us consider large States that have over 12 Members of Parliament in the Lok Sabha. Further, in these States, let us grade the INC and BJP as electorally relevant or otherwise. A party is determined relevant(rated 1) in a given State if it’s within the first two positions electorally. Else it gets a 0. In slightly complicated situations — such as the BJP in Punjab/ Maharashtra — the party gets a 0.5. Typically, there are states where both are relevant, both are irrelevant and some where only the INC is (Andhra Pradesh, for instance). As discussed earlier, there aren’t many parts of the country where the BJP is present and the INC is not.
Once we do this simple classification of states, a picture of each party’s natural constituency and electoral alliance emerges. Let’s begin with the BJP since it has the problem of a smaller footprint across the nation. The first fact that strikes one when looking at the states where the BJP is relevant and where it isn’t is this: a reinforcement of the conventional opinion that the BJP is an upper caste party. In states where the party is relevant, the average percentage of upper caste* presence is 22.7%. In states where the party is irrelevant, the upper castes form 9.7% of the population. That’s a clear 13 percentage point divergence which can’t be dismissed even if the rather wide range of the contributing data points is taken into account. Just as crucial is the opposite trend amongst Muslims, confirming the other piece of conventional wisdom that the BJP has a problem with Muslims. Or, the Muslims have one with the BJP. In states where the BJP is relevant, the Muslims, on average, form 10.55% of the population; where the party is irrelevant, the corresponding number is 21.12%. The divergence again is 10.57 percentage points. Similarly, the divergence of the OBC population is about 5 percentage points against the BJP; that is, on average, a larger OBC population in a given state compared to the norm is detrimental to the BJP. Dalit(SC) votes are distributed evenly amongst both sets of States while the divergence of the Scheduled Tribes seem to favor the BJP.
Another simple way to measure is to measure basic correlation coefficient for the various groups with BJP’s relevance. They stack up along the lines of the above analysis — the Upper Caste population strength and the Tribal population are positively correlated while that of the Muslims and SCs are negatively correlated. The OBCs have a very slight negative correlation and can be considered as neutral given the data is unclean. If one were to compare this classification with that of the INC, a remarkably similar structure emerges. The INC too is a party that depends on higher percentage of upper castes and a slightly lower presence of both OBCs and Dalits for its relevance. The correlation coefficients of upper castes and Tribes are highly positive while that of Dalits and OBCs are highly negative with INC presence in these states. Unlike the BJP though, the Muslim vote does not impact the INC’s relevance negatively.
The significance is not just in the similarity of the relevance of these two parties but in that of their irrelevance. Both parties start losing relevance gradually when the OBCs and Dalits put together cross 60% of the population. The BJP loses it quite dramatically near the threshold while the INC starts losing it slightly more gradually owing to some Muslim presence. This analysis, as discussed previously, does not mean that the Dalits and OBCs don’t vote for the main national parties. But simply that their demographic strength beyond a certain threshold makes a caste formation that’s driven by traditional upper caste polity very difficult to sustain. There is space for OBC and Dalit driven formations — resulting in SP, RJD, JDU, BSP, DMK, AIADMK etc. It is also the case in these states of Bihar, UP and Tamil Nadu that the OBCs and Dalits when put together exceed 75% of the population. In the case of Tamil Nadu, they exceed 90%, rendering either of these parties outside the top 4.
*Upper Caste for the purpose of this analysis is the set of all population excluding Dalits, OBCs, Tribals and Muslims. Christians have been excluded in the case of Kerala.