In 1937, Jinnah fought elections as the president of Muslim League on the plank of "Muslims in Danger". Keep in mind that there were separate electorates then which means Muslims could only vote for Muslim contestants and Hindus only for Hindu contestants. He lost badly. Muslims across the Indian subcontinent rejected Muslim League. Worse, Congress won with huge majority in Muslim-majority areas such as Khyber-Pakhtunkhwa (then called Frontier).
Desperate for power and too egoistic to accept defeat, he changed his narrative from "Muslims in Danger" to "Islam in Danger" and aroused rabid religious passions, especially on Direct Action Day where he and his fellow aristocratic Muslim Nawabs abetted Hindu-Muslim riots in which more than 6000 died. He warned that "India will either be divided or destroyed."
Sensing that it is better to have this cancerous arm amputated in the beginning itself instead of letting it spread across the body - Gandhi, Nehru, Patel and Azad reluctantly agreed for Partition of India. In his final days, Jinnah seems to have realized his mistake and his secular European values kicked back, which can be seen in his famous August 11 speech in the Pakistan's Constituent Assembly. But then it was too late. MJ AKbar, India's premiere journalist narrates the story of Jinnah and partition in his trademark style sprinkled with humorous anecdotes.