Fatima Jinnah won a landslide from Bengal with the help of Mujib but the results were rigged and Ayub became the president of united Pakistan. The Bengalis never forgot this and became to ponder on the insignificance of their Votes and Rights.
It started long before 1964. One very important (but often ignored) development was the 1954 provincial elections held in East Pakistan .. Elections were due in 1951, but the Muslim League (ML) used delay tactics (though it didn't help them in the long run). The elections resulted in a landslide victory for the socialists and nationalists i.e. United Front which won 228 seats in a House of 309 (including nine reserved seats for women). On the other hand, the Muslim League, the party in power directly or indirectly ever since 1937, managed to get only 7 seats ... This heralded the rise of Bengali Nationalists ..
But On May 30, just after two months, the ministry was dismissed and direct governor’s rule was imposed.... Now ML knew that in case general elections were held, the Bengali Nationalists would come to power in the center as well (as Bengalis formed the "Majority"), and the political hegemony of ML would be over ...
This was when ML decided to use "Islam" as a political tool against the socialists of East Pakistan ... And those Mullahs who had openly opposed Jinnah and proudly rejected Jinnah's "unIslamic" ideals, were invited to join ML (see Munir Report of 1954 for details) ....... The country was named "Islamic Republic" in 1956 ... We were the first one in the world to add prefix "Islamic" to our republican status .. ... Elections were further delayed by ML ..
In 1957 most of the detractors came together in the left-wing and secular National Awami Party (NAP) and were confident that the party was in a good position to win the most seats in the promised direct elections (that were to be held in 1958). But then first Martial Law was imposed in the country in late 1958 by the "elected" president of ML who invited Army to take over hoping that this would keep Bengalis (and others) permanently away from the corridors of power, as they had almost no representation in the predominantly Punjabi Army of Pakistan ... (But this proved to be "catastrophic" in the long run ... No amount of "Islam" or "military force" could hold Nationalist Bengalis for long ... And in 1971, we paid the price of "selfish" policies (adopted by the ML) ..
I don't think we can blame Mujeeb alone, (or Yayha or Bhutto even) for the 1971 debacle. Mujeeb may be a traitor for West Pakistanis, but for the East Pakistanis he was a true representative of the people, unlike Nawaz Sharif. Nawaz is a
gaddar who turned against the very establishment who imposed him on Pakistan in 1980s, and then the country and its people for rejecting him. He has already done more damage to Pakistan than Mujeeb did to (West) Pakistan in his lifetime.