Is Pakistan constitution Islamic?

In his article Pakistan's Constitution Conundrum, Muhammad Asim argues that Pakistan's constitution is not Islamic. He argues that having Islam as state religion or presence of Federal Shariat Court, which can declare any law unislamic, does not make Pakistan's constitution Islamic. According to him, the process of developing laws through a democratic system is completely different from 'extracting laws from Islamic texts in the process of jurisprudence'.

He presents his case as follows:

'In a democratic process, elected lawmakers come together to develop laws as they see fit. There are no constraints as to what they can legislate for, with only a majority of some sort required to pass any particular law. There is no requirement for the legislators to have previous legal experience, nor that they be experts on the subject matter at hand, though technical advice can be sought if required.

In Islam, many matters are clearly defined as being legal or illegal, such as the consumption of alcohol, adultery and interest-based transactions. In areas where definitive rulings do not exist or new realities are encountered, a legal expert is required to extract a ruling from Islamic texts. If the legal expert does not possess technical expertise in understanding a particular subject matter, then he or she is allowed to call upon the help of specialists to apprise them of the reality - for example, a doctor to explain the technical aspects of human-cloning. This process is known as Ijtihad.

In a situation where a numerous legal experts have extracted an array of opinions on the same matter, based upon either a variation of their understanding of the technical reality or use of different principles in accessing non-definitive Islamic texts, it is then up to the ruler of the state to adopt one opinion for it to become the sole reference point in law.

A problem therefore is apparent in the Pakistani law-making process: legislative chambers that are filled with individuals unqualified to extract laws from Islamic sources from a jurisprudential perspective are enacting laws for the country to follow simply according their own limited knowledge and experience rather than turning to divinely revealed guidance.'

Asim further argues that 'the powers of the executive are ill-defined between the president and the prime minister, while according to Islam these should be vested in a single ruler and thus enable him to adopt laws extracted according to Islamic texts. This is crucial, as under the current democratic system even if both legislative chambers of the National Assembly and Senate were filled with qualified jurists, the mechanism to enact an extracted legal opinion into law would be missing, leading to confusion and potential conflict.'

Asim's arguments can be analyzed in at least two ways, as a critique of the democratic system or as an explanation of Islamic system. Since Asim's focus is on the later, I ignore the critique on democratic system and center my analysis on his explanation of Islamic system. I argue that Asim has presented a very simplified version of Islamic law/constitution that needs to be problematized. Lets analyze Asim's arguments one by one.

1. In Islam, many matters are clearly defined as being legal or illegal, such as the consumption of alcohol, adultery and interest-based transactions.Contrary to what Asim is implying, Islam not only defines very few matters as legal/illegal but even those matters that are clearly 'defined', cannot be implemented solely on the basis of Quran and Sunnah of the Prophet (PBH). Lets look at the examples Asim himself has given. Quran has made consumption of alcohol illegal but there is disagreement on what is the minimum amount for a person to be charged. Similarly, although riba (usually translated as interest) is illegal, there is disagreement on how similar riba is to today's interest. So, even those rulings of Quran which Asim argues as definite, are open to disagreements and need human agency/agreement before they are implemented. My view and the view of many Muslim jurists is that Quran and Sunnah primarily give principles and leave actual rules/laws for the Muslims to decide.
2. In areas where definitive rulings do not exist or new realities are encountered, a legal expert is required to extract a ruling from Islamic texts. If the legal expert does not possess technical expertise in understanding a particular subject matter, then he or she is allowed to call upon the help of specialists to apprise them of the reality - for example, a doctor to explain the technical aspects of human-cloning. This process is known as Ijtihad. In a situation where a numerous legal experts have extracted an array of opinions on the same matter, based upon either a variation of their understanding of the technical reality or use of different principles in accessing non-definitive Islamic texts, it is then up to the ruler of the state to adopt one opinion for it to become the sole reference point in law.  I agree with Asim and I think Asim will agree with me that more often than not, on every issue there are more than one opinion of Muslim jurists. Therefore, someone has to decide and it is usually the ruler of the state. The question now becomes who is the ruler of the state. Does Islam prescribe a specific type of ruler or a specific system for choosing a ruler?
3. A problem therefore is apparent in the Pakistani law-making process: legislative chambers that are filled with individuals unqualified to extract laws from Islamic sources from a jurisprudential perspective are enacting laws for the country to follow simply according their own limited knowledge and experience rather than turning to divinely revealed guidance. Here Asim contradicts himself. He argued above that rulers can borrow legal/Islamic expertise and then can decide among different opinions available. Now, he argues that as legislators are unqualified to extract laws from Islamic sources, they are not qualified to serve as rulers. Why Pakistani legislators need to extract laws from Islamic sources themselves when they can take the advice of Muslim jurists (as Asim allows to other rulers)? 
4. If the purpose of the argument above is to show that Pakistani legislators do not take this advice (even when available) and instead make laws on the basis of their own whims then, it can be argued that Pakistani constitution is not inherently unislamic only the legislators (or the people who elect them again and again) are.
5. This leads us back to the questions asked at the end of point 2 above. Has Islam prescribed a political system (so that we can get rulers/legislators)? Unfortunately or fortunately, Islam has not favored any specific political system. So, not only Islam has left small matters of alcohol consumption for the Muslims to decide on, but it has also left bigger matters of deciding about the political system to the Muslims. Again, we can go back to Muslim jurists (to extract a ruling about Islamic political system) but unfortunately, they are also divided. Some say a monarchy is an Islamic system, others argue that a democratic system is an Islamic system.  
6. The powers of the executive are ill-defined between the president and the prime minister, while according to Islam these should be vested in a single ruler and thus enable him to adopt laws extracted according to Islamic texts. This is crucial, as under the current democratic system even if both legislative chambers of the National Assembly and Senate were filled with qualified jurists, the mechanism to enact an extracted legal opinion into law would be missing, leading to confusion and potential conflict. This argument of Asim is especially strange. Where in Quran or Sunnah it is written/given that there should be a single ruler? Infact, the powers of executive are much more clearly defined now then it was in the times of Righteous Caliphs, model of Islamic rule according to a large majority of Muslims. It can be argued that the present system of President/Prime Minister and Parliament is quite similar to caliph and senior Sihaba in the times of Righteous Caliphate. 

I hope I have made clear that Pakistan's constitution is not unislamic. If we accept Asim's arguments, then Iran and Saudi Arabia are both Islamic constitutions. Both these constitutions (or Basic Law in case of Saudi Arabia) were approved by Islamic jurists. However, both these countries' jurists consider the other system as unislamic. So, which Islamic jurists are we to believe? Or are we to believe the Saudi rulers whose Islamic credentials are next to none, probably even lower than Pakistani legislators? 

If it only based on Muslim jurists' opinion, rulers in Muslim -majority countries can easily find jurists to approve their constitutions. Pakistani government has also got a fatwa that constitution is Islamic Religious-decree: 'Constitution completely in line with Sharia'