Mr Advani, after all, is no ordinary BJP leader. The rapid rise in Mr Modi's profile in the past few years cannot take away from the fact that the party he now dominates has been built on a core of hard Hindutva by Mr Advani, the consummate organisation man. Mr Modi's backers in the party are loud, articulate and visible everywhere; they drown out those at the middle levels of this cadre-based party who will naturally be uncomfortable with the nature of the exit of the leader to whom many think they owe their party's rise in recent years. Mr Modi will have a delicate repair job to do to the organisation's morale and help rebuild consensus within it. Notably, he has not hitherto been much of a man for consensus.
Mr Advani's departure, if it sticks, will be the end of an era. Few remain who were active in party politics in the 1950s - by the middle of that decade, he was already secretary of the Jan Sangh in Delhi. Hardly a Nehruvian ideologically, Mr Advani nevertheless seemed to share with Atal Bihari Vajpayee and others of that generation from all parties a commitment to the forms of constitutional politics. In leading the BJP's Ayodhya campaign, he understood before many others the nature of the rising Indian middle class, and that slowly increasing economic growth could sometimes deepen rather remove divisions. The BJP's ideology, as it is today - an uneasy blend of religion-based hyper-nationalism, middle-class awakening and genteel claims to probity in its internal affairs - is perhaps more a reflection of Mr Advani than of any of its other founders, including Mr Vajpayee. But even those who change parties are, eventually, let go, when their own ideology outgrows them. Perhaps the most powerful example is of Margaret Thatcher, who transformed Britain's Conservatives and the country, but nevertheless was ruthlessly dispensed with by her party when she became an electoral liability. The sad fact is that this transition to a younger generation was inevitable. But it need not have been so shabbily carried out - and that it was reflects poorly both on the ambition of the old and on the arrogance of the new.