Rahul Gandhi doesn't expect to be prime minister in 2019. His target is 2024. Time is on his side. In May 2024, he will still be only 53. Narendra Modi, even if he wins a second term in 2019, will be 73 in 2024. Rahul believes that his time will then have come.

Prediciting so far into the future in politics is of course foolhardy. Events can overturn the best-laid plans. Still the Gandhi family's blueprint is clearly etched. Sonia Gandhi will hand over the Congress presidency to Rahul in the course of the next one year, possibly earlier. She will turn 70 in December 2016: a good time to bequeath the fief.

Congress old-timers who've blocked Rahul's coronation for a while, fearing their own obsolescence, have more or less come around. Rahul's hyperactivism in recent months has been directed as much at them as at the BJP.

The old guard in the Congress has for long doubted whether Rahul had fire in his belly. They persuaded Sonia to carry on as president last year. She radiates a European sense of purpose. Her body language is assertive. She speaks with firmness that brooks no dissent.

Rahul, half-European, quarter-Kashmiri and quarter-Parsi, is milder. It has taken him 12 years in Parliament to capture the aggression his mother projects effortlessly. And yet, when it comes to the crunch, Sonia is ruthless, Rahul conciliatory. A recent example highlighted the difference between mother and son. When the party journal Congress Darshan called Sonia's father a fascist she had the magazine's editor sacked in 24 hours.

Sanjay Nirupam, in overall charge of the publication, was also on the chopping block despite his contrite apology. When Rahul visited Mumbai, he met Nirupam and accepted his apology.

Sonia was still furious. The F-word (fascist) had hit a raw nerve. She insisted on Nirupam's sacking till Rahul intervened. Nirupam survived.

Unfortunately for Rahul, he is not a natural politician. But then neither was his father. Rajiv Gandhi joined politics at the age of 36, contesting his first Lok Sabha by-election in 1981 from Amethi, months after younger brother Sanjay Gandhi's death in an air crash.

By 40, he was prime minister, following his mother Indira Gandhi's assassination. At 46, he was dead.

By contrast, Rahul's progression has been glacial. He will be 46 this June and has still not held a constitutional post. As vice-president of the Congress, a family company, he has not had to deal with meaningful opposition within. He doesn't have to report to anybody. He isn't accountable to anyone.

At his age, Rajiv had been prime minister for five years, faced huge crises, including the defection of close confidants VP Singh, Arun Singh and Arun Nehru, carried out complex negotiations in Sri Lanka, Punjab, Assam and Mizoram, and countered fierce media attacks over Bofors before becoming an outspoken opposition leader in Parliament for over a year.

In comparison, Rahul has had it easy. Out of power, he has the advantage of attacking Prime Minister Narendra Modi without fear of serious retaliation. As the prime minister, Modi has to preserve the impression of being above the fray. The aggressive campaigner Modi of 2014 was a very different politician from the high-minded prime ministerial-Modi of 2016.

Rahul has taken full advantage of this. But the question remains: does Rahul have the stomach for the top job?

The same question was asked of Rajiv when he assumed the prime ministership following his mother's assassination. In the recently published second volume of his memoirs, President Pranab Mukherjee writes that on the flight from Calcutta to Delhi after hearing the news of Mrs Gandhi's assassination, Rajiv asked him if he "would be able to manage as prime minister".

A few months after that conversation, I interviewed Pranab Mukherjee. After also interviewing others who were on that Calcutta-Delhi flight along with Rajiv, this is what I wrote in my biography Rajiv Gandhi: The End of a Dream (pg 136-139), published by Penguin:

"After reading the message twice over I asked the policeman near our car to do three things immediately," Mukherjee told me. "First, to ascertain whether a pilot could be contacted at Calcutta by wireless and, if so, to keep him standing by to fly to Delhi by an air force jet. Second, to contact simultaneously the air force bases in Kolaikunda and Calcutta and keep one air force jet standing by at both places. And third, to keep us informed every five minutes over the car radio about the latest news from Delhi."

By now it was 9.45am. Mukherjee, Ghani Khan Chowdhury and Rajiv (still accompanied by his security officer) abandoned their Ambassador and got into a Mercedes (which was a part of the convoy) and sped off towards the junction at Kolaghat. "We thought the Mercedes would make better time than the Ambassador, hence the switch," Mukherjee told me.

Meanwhile, Rajiv put on the car radio and tuned into BBC. At around 10.00am the three men, sitting silently in the back seat of the Mercedes, now speeding towards Kolaghat at eighty miles per hour, heard the news of the assassination with shocked disbelief. BBC did not confirm Mrs Gandhi's death but did report that she was at the All-India Institute of Medical Sciences (AIIMS) in critical condition. The broadcast went on to give details, sketchy as they were then, of the shooting and the suspected assassins. The men sat in the car in grim silence. "The only words Rajiv spoke," recalls Mukherjee, "turning to look sideway at me, were: 'Is this all she deserved?'"

The three men flew by helicopter to Calcutta, 30 miles away. Two aircrafts were standing by at the Calcutta airport. Within minutes Mukherjee, Chowdhury and Rajiv were on board an Indian Airlines (IA) Boeing in which they were joined by Uma Shankar Dikshit, his daughter-in-law Sheila Dikshit, Lok Sabha speaker Balram Jakhar and veteran Congress leader Shyamlal Yadav. Accompanying them were Lok Sabha secretary S Aggarwal and Rajya Sabha secretary S Kashyap.

The IA Boeing left Calcutta for Delhi at 1.15pm. Inside the plane the mood was sombre. Mukherjee, Dikshit and Rajiv sat in seats 2A, 2B and 2C, just behind the cockpit; Rajiv was seated next to the aisle. Within minutes he made his way to the cockpit where he had spent 12 of the last 16 years as an airline pilot. In the cockpit, the atmosphere was equally tense. The pilot, in continuous touch with ground control, kept Rajiv informed of the latest situation in New Delhi.

At around 1.25pm the news Rajiv had subconsciously expected, but dreaded to hear, came crackling over the aircraft radio. Mrs Gandhi had succumbed to her injuries.

A few minutes later, at 1.30pm, an expressionless Rajiv came out of the cockpit and told Mukherjee and Uma Shankar Dikshit that Mrs Gandhi had died. His voice was calm, his composure striking. "He was in complete control of himself," recalls Mukherjee, "though he was obviously in deep shock."

Mukherjee, as the seniormost minister in Mrs Gandhi's cabinet, was now unofficially in charge of the government. "I broke down completely and wept," he confessed to me. "I went to the bathroom and was there for half-an-hour trying to compose myself. I don't remember what happened for the next 30 minutes."

Balram Jakhar, who as speaker of the Lok Sabha would have a pivotal role to play in ensuring an orderly succession, finally asked Mukherjee bluntly: "Do you think Rajiv should be inducted as prime minister?"

In his interview with me, Mukherjee recalled the conversation: "I said yes, he must be inducted as prime minister. Further, I pointed out that if we announced Mrs Gandhi's death at that stage, the country would be without a government. President Zail Singh was also out of town, remember. I urged them all to ensure that All India Radio and the national TV network should not announce the death till Rajiv had been sworn in as PM."

Everyone agreed with Mukherjee on this point and it was thus that AIR and Doordarshan did not officially broadcast the news of Mrs Gandhi's death till evening, long after the international media had confirmed the news. By then Rajiv was about to be sworn in as the prime minister.

Rahul has a bit of Rajiv in him. But he has a lot more of Sonia. The mother-son duo run a tight ship. The Congress has no credible leader to challenge the family. Historian Ramachandra Guha said recently that Rahul is unfit to be prime minister because he simply isn't bright enough. Guha is wrong. You don't need to be brilliant to be prime minister. If you did, a neuroscientist or physicist would be one. What you need is common sense - and the common touch.

The Budget session of Parliament beginning on February 23 will reveal whether Rahul has matured as a political leader. The first job of such a leader, of course, is to reject dynastic privilege and build the party of Jawaharlal Nehru, Sardar Patel, Netaji Subhas Bose and Maulana Azad into a genuinely democratic organisation.

That task proved beyond Indira, Rajiv and Sonia. It could alas prove beyond Rahul.