As I have written many times, I believe in democratic mechanisms within a framework of constitutional limits on legislative powers.
There is no way to achieve fair and just government in a strictly secular democratic system, and that should be obvious.
Separating law and government from Revelation is an fatal error. Renouncing the prime importance of the Shari’ah, and advocating the formulation of laws by subjective, self-interested politicians is a renunciation of even the possibility of fair and just government.
Of course, the government must have the freedom to enact laws not included in the Shari’ah, as long as they do not contradict with the Shari’ah; that is a practical reality, and this was done in the time of the Khulafah Rashideen, and there is nothing wrong with that.
However, the idea that the state should have no religion, that it should be secular, condemns the population to enslavement to the whims and caprices of politicians who may be influenced one way or another by external pressures and personal interests. That is a disaster.
Even constitutional limits cannot save secularism from this fate because the constitution will be a document drafted by men, amendable, and inevitably derived from whatever morality may prevail at the time of its drafting.
To dismiss the supremacy of the Shari’ah is either to deny its Divine origin, or to deliberately prefer an inferior, subjective, imperfect source of law; it is either blatant kufr or profound self-contradictory illogic.
That said, it is depressingly true that many people who talk about establishing Shari’ah over emphasize the technical implementation and ignore the practical impact on society.
They imagine that state imposition of Zakah, for instance, will instantly wipe out poverty without any additional policy measures. They imagine that the Hudood will end crime, and so on. These are fantasies, escapist Utopian rhetoric, used by well-meaning, but ill-informed people who are either unwilling or unable to analyze complex realities.
Government policy must not only conform to Islamic Law, but it must also bring Islamic results.
Frankly, and based on my own experience, I believe that many who talk about establishing an Islamic state are completely disingenuous, and they do not have the slightest desire to live under the Shari’ah, but they simply use the rhetoric to excel in the Islamist niche of the political spectrum. If they attained power, very little would actually change from the status quo, and I think we have recent precedents that support that view.