Pakistan fell, a few years after independence, into military rule. I remember reading a few years ago that this was because of the deaths of its founding father and first prime minister (which is echoed in this answer). Also, the country did not become an Islamic republic until years after these deaths. That has made me look into what the founders originally wanted Pakistan to be.
Of course, it was intended to be a Muslim-majority country. However, I cannot find many primary sources into what kind of policies they wanted to enact with the exception of the Objectives Resolution of 1949. However, people present at this assembly, like Sris Chandra Chattopadhya, said that Jinnah had wanted a secular government. That seems to be somewhat supported by Jinnahs constitutional reform plan. However, it's quite unclear there if he wanted Islam to be a state religion for the country or not.
When searching up Jinnah's name, I discovered texts where he is idolized by Pakistanis and demonized by Indians. However, I am having a difficult time finding what the man actually believed in. I found this BBC article in which they are referring to a speech from the 11th of August 1947, in which he explicitly states that he wants a nation in which religion is a personal rather than political matter. However, according to the same article, no known recordings of that speech exists. That leads to the question, are there any other speeches or writings of Jinnah which can elucidate what kind of nation he envisioned Pakistan as?
A full transcript of Muhammad Ali Jinnah's August 11, 1947 speech can be found on the website of an instructor at Columbia University here.
In the speech, he makes at least two statements that seem to support a vision of a secular government with religious liberty:
[]… You will no doubt agree with me that the first duty of a government is to maintain law and order, so that the life, property and religious beliefs of its subjects are fully protected by the State.
[] Now I think we should keep that in front of us as our ideal, and you will find that in course of time Hindus would cease to be Hindus, and Muslims would cease to be Muslims, not in the religious sense, because that is the personal faith of each individual, but in the political sense as citizens of the State.
At least a portion of the speech was recorded and can be heard on video at YouTube. Some of the quoted text above can be heard in the video. It appears that the speech itself was given in English, so we are dealing with the actual words of Jinnah rather than some translator's interpretation of them.
Jinnah was a lawyer whose 'proffers' were of a take it or leave it nature and which did not bind him or the State he envisaged in any way. Precisely because he was a lawyer, he did not sketch out any 'vision' of his own. That was not his business. His position in politics was as the Chief Representative of the Muslim League which demanded to be treated as the sole voice of the Muslims of British India. The core demand of the League is expressed in the Lahore Resolution which states - geographically contiguous units are (to be) demarcated into regions which should be so constituted, with such territorial readjustments as may be necessary, that the areas in which the Muslims are numerically in a majority as in the North-Western and Eastern Zones of India, should be grouped to constitute “Independent States” in which the constituent units shall be autonomous and sovereign.'
Sovereignty means that the successor State, or States, would not be bound in any way. It is likely that Jinnah himself wanted equal opportunity, regardless of creed, and he certainly took the initiative to appoint non-Muslims to high offices or to entrust them with important duties- e.g. writing the National Anthem. However, precisely because Jinnah was a lawyer, we would be unjustified to say that Jinnah had a 'vision' which was subsequently betrayed. Had he really wanted to restrict what Pakistan could do, then he would have demanded a qualified sovereignty based on a pre-existing Constitution.
This becomes clear when you look at what had happened in Ceylon. There the minorities accepted a deal whereby there was strong Constitutional protection of their interests in return for ceding self government under universal adult suffrage. Jinnah was rejecting this route. He was not alone. All the minorities- including Dalit Hindus- rejected Gandhi and the INC at the second Round Table Conference. Though, in 1935 a Federal structure was envisaged, Jinnah and the minorities rejected it completely. Why? Even if constitutional safeguards of minorities was feasible, it was not what they wanted. Why? Jinnah's crucial claim, his 'vision', was that Muslims constituted a separate Nation of a sovereign type. Some Indian Muslim divines opposed this notion as 'wataniya'- i.e. a narrow Nationalism, incompatible with Islam which is universalist. However, once Pakistan was a reality, they would have to accept that 'hubb al watan min al Islam'- patriotism too is part of Faith. In other words, whether or not the demand for Pakistan was un-Islamic, once it existed as a sovereign nation, no Muslim had any right to object to it.
The precedent for what happened to British India- viz. its partition on Religious lines- was what happened when the Ottoman Empire was dissolved. Greek speaking Muslims went to Turkey. Turkish speaking Christians (presumably of Greek heritage) went to Greece. All this happened under the auspices of the 'secular' Ataturk. Indeed, at around the same time, Ireland was partitioned on essentially sectarian grounds. It seems religious identity exists even amongst those who aren't religious at all.
After Jinnah's death, some of his admirers were dismayed by the 'Objectives Resolution'. But we can't say this was a betrayal or subversion of Jinnah's intentions. He wanted sovereignty for Pakistan because he believed sovereignty was in the best interests of the Muslims of India. True, this left those on the wrong side of the border in the lurch. It is also true that Jinnah's 'hostage theory'- i.e. the Hindus would protect the Muslims in return for Muslims protecting Hindus- broke down immediately. It may be that Jinnah himself felt his 'vision' had not been realized. But, there is no evidence that he ever said so. It does seem, however, that Jinnah- like other leaders- was shocked by the scale of the violence and ethnic cleansing which broke out even in big Cities and prosperous, relatively well-developed, districts. By 1949, both India and Pakistan had hardened in their attitude to minorities. India forbade the re-entry of displaced Muslims who lost citizenship. The Indian Constitution would uphold things like cow protection and insist that the national language be written in the Devanagari script of the Hindus. In Pakistan, the situation of minorities was even worse and ethnic cleansing of Hindus from the East continued in the Fifties and Sixties.
Pakistan was slower than India in adopting a constitution and declaring itself a Republic. But when it did so, in 1956, it was the first country in the world to declare itself an 'Islamic Republic'. This changed nothing on the ground. In particular, the Ahmadiyyas (a sect viewed by some as non-Muslim), were not stigmatized. They held high offices and contributed much to the prosperity and advancement of the country. It wasn't till after the loss of the East Wing that Pakistan adopted an explicitly Islamist constitution with unfortunate results for the Ahmadiyyas. Still, the fact is Z.A Bhutto was promoting himself as a Socialist. It wasn't till the Army moved against him that, under General Zia, the State apparatus was made explicitly Islamist.
Why was democracy weak in Pakistan? The answer is that the East Wing was more populous and had a longer tradition of democratic politics. Thus, democracy would have shifted power from the West to the East- which was also earning more foreign exchange through the export of jute. However, in West Pakistan, the Civil Servants proved incompetent and corrupt. Furthermore, the rise of military men- like Nasser in Egypt- in other Muslim countries caused the Generals to think their own rule would be welcomed.
Since the army had good grassroots support through its network of ex-servicemen in the villages of Punjab and parts of the NWF, it could displace the embryonic class of lawyer/politicians in the West wing. However, it is important to remember that it was the aristocratic lawyer, turned populist, Z.A Bhutto whose machinations sidelined the Army and opened the door to Islamization.
The paradox of Pakistan is that it was Western educated lawyers like Jinnah and Bhutto who let the Islamist genie out of the bottle. Was this inevitable? Yes. There is a mullah in every village. People look up to them because they help resolve disputes and they teach the kids to lead a moral and spiritual life. By contrast, 'civil society' is relatively weak in the countryside. However, it must be said that West Pakistan made some great strides in primary education etc. Hence Ayub Khan's rule could generate quite fast economic growth and a feeling of prosperity in the West wing. Sadly, military adventurism was his undoing.