Had Modi not been popular among masses and party ranks, RSS would not have bothered to put its weight behind Modi. In one sense, even RSS has bowed to the essence of democracy where the most popular leader is given the mandate to lead the party.
In fact, Modi's elevation is somewhat similar to the American primaries that provides for leadership selection through democratic means. This is in sharp contrast to leadership criteria that majority of political parties follow in India.
The leadership criteria for these political parties is that you have to be either a son, daughter or a closer relative of the reigning leader for aspiring to lead that party in elections. This is prevalent across the country, from north to south.
From Farooq Abdullah-Omar Abdullah in Jammu and Kashmir to Prakash singh Badal – Sukhbir Singh Badal in Punjab to Chautala family in Haryana, Mulayam-Akhilesh In UP, Lalu-Rabri and family in Bihar, Patnaik family in Orissa, NTR and Reddy families in AP and Karunanidhi family in TN.
It is very difficult for a common party worker of these parties to aspire for the leadership position. BJP and Communist parties are perhaps the two exceptions.