Years ago I was sitting in the house of a leading astrologer MR K.N.RAO. Another astrologer who had appeared in TV told us that Rahul will join BJP. We were both stunned but then it is very good way to shock people to get attention.
Nehru was the prime minister who ruled till his death and never lost elections.
The second one was the Indira Gandhi who ruled the country, lost and regained power and also lost her life in power.
The third one was Rajiv Gandhi who lost his life when he was not in power.
The fourth one was Sonia Gandhi who most likely will not hold official power.
If one sees the patterns first generation held power completely, the second one marginally, the third one had less power and the 4th one literally has no official power.
There is a gradual reduction of power. Mostly Rahul or Priyanaka will not hold any high office.
Second pattern was two had violent death one in power and other with out power.
The third pattern is the first generation was male second one was female then the third one was male and 4th one is female. There fore there is less chance of Priyanaka coming into power.
Nehru dynasty will hold power surely till Sonia is alive. But someone from that dynasty becoming prime minister has less chance.
India was ruled longest by the mughal dynasty which had 6 kings before it cracked up.
May be one more generation they can hold power but ultimately there is waning of influence.
One can say the influence of Nehru dynast will come down slowly and surely. Wheels of life takes people up and down, even the lineages.