The 1946 elections for Congress presidency were very prominent, because the President would lead the free india's first government. Gandhi asked all 16 states representatives and Congress to elect the right person and Sardar Patel's name was proposed by 13 state representatives out of 16. But, Gandhi requested Patel to step down in favor of Nehru. He honoured Gandhi's request, and stepped down. That's why Jawaharlal Nehru became the first Prime Minister of India.
After the death of Lal Bahadur Shastri in Jan 1966, top leaders of Congress party could not come to a unanimous decision for the next Prime Minister. The prominent leaders at that time were Morarji Desai, K.Kamaraj, and Jagjivan Ram. They could not agree upon a consensus candidate amongst themselves. They reluctantly placed the crown on Indira Gandhi's head, believing errorneously (and what a costly error it would later prove to be), that they could keep her under their control.
In 1971 elections, Indira Gandhi's promise was "Garibi Hatao" (by Socialist economy model), and all the economists knew how bad that was, and most of the things were undone by P.V.Narasimha Rao and Manmohan Singh. But, uneducated people were not aware of that, and they all voted for Indira Gandhi.
In 1977 elections, Congress Party was defeated badly, and Indira Gandhi was defeated in Rae Bareli, and her son Sanjay Gandhi lost in Amethi. In 1979, Indira Gandhi told Charan Singh that she would support him in forming the government. Then, Charan Singh defected the Janatha party with 64 MPs. Even, if Indira Gandhi supports him, still he would not have got majority in Parliament, because she had only 154 MPs. But, still then president Neelam Sanjeeva Reddy invited him as Prime Minister. On the day before vote of confidence, Indira Gandhi withdrew the support. Charan Singh had to resign, and he became the only prime minister who did not face Lok Sabha even once. After that, Jagjivan Ram and few others met President and told him that, they can form the government, by all other MPs of Janatha Party, AIMDMK, and few other small parties. But, President rejected that, and he dissolved the Lok Sabha immediately. That was when, Chandrasekhar (Then president of Janatha Party) wanted to remove the president Neelam Sanjeeva Reddy by impeachment. But, later they decided to not call for impeachment. That was the only time, when the Members of the electoral college wanted to call for impeachment.
In 1980, Indira Gandhi could easily win because of the inability of Janatha Party, where there were splits. In the same year, Indira Gandhi's younger son Sanjay Gandhi died. After Sanjay's death, Rajiv Gandhi was asked to join politics by his mother. He contested and won from Amethi (His brother's constitution) in 1981. He became General Secretary of Congress in 1982. In 1984, Indira Gandhi was assassinated, and he became the Prime Minister on the same day. He wanted to utilize the sympathy, and called for dissolving of Lok Sabha. As expected, Congress won with great majority.