That Mr. Gandhi has been an unfair beneficiary of his family background has been a favorite grouse of the urban middle class, even though the fact in plain sight is that the young of the Indian elite are as blessed by their families as Mr. Gandhi is by his. Across the social rungs in India, the family serves its own well. And in return it exerts such a powerful influence over the individual that a baffled former coach of the Indian national cricket team, an Australian, accused the Indian family system in one of his memoirs of creating weak men and thus emasculating Indian cricket. (Indians think that he was the real problem.)

In a country where having a family is a sign of normality, where even trees are still ritually married off to humans in some places, one would imagine that the politicians would consider it important that they display an amiable spouse and two adorable children who wave at people. But the fact is that many of India’s top politicians are single or of uncertain marital status. Mr. Gandhi’s pledge of bachelorhood will not diminish him in any way as the Congress party heads for elections next year or sooner.

His archrival, Narendra Modi, is also single but in a more complicated way. Mr. Modi, 62, the most popular leader of the Bharatiya Janata Party and the chief minister of the western state of Gujarat, is expected to be his party’s prime ministerial candidate. Mr. Modi lives alone. On Monday, when he went to watch the 3-D version of the film “Titanic,” he was accompanied by several members of the Gujarat legislative assembly. That has to be the very definition of being single. However, there is an impoverished woman in a small village of Gujarat who is widely believed to be his wife. Mr. Modi has never spoken about his marriage, nor has he denied journalistic accounts that portray the woman as his wife.

There is a difference in the singlehood of Mr. Gandhi and that of Mr. Modi. Mr. Gandhi dates women. Mr. Modi does not. His cultural background is such that his followers claim or imagine that he has taken a vow of celibacy, something a particular kind of married Indian man does, usually without the permission of his wife.

The last time the B.J.P. was in power, the prime minister was Atal Bihari Vajpayee, who was also single.