There is no real practical difference between Islamists and secularists; just the different belief and values systems each uses to guide them in crafting man-made laws. The Islamists talk about #Shariah, but their entire governmental model, and almost any laws they would enact spring from human minds; let’s be honest. The differing belief systems matter, of course, but when you are talking about the legislative process, both are necessarily dependent on reasoning.
I am not saying that as a criticism, but as a clarification; because the Islamists try to put forth the idea that THEIR laws will all be Divine in origin, which is just false. If you are going to say “we need to follow the governmental model of the Khulafah Rashideen”, ok, they were men; men who developed as best they could a system of government that addressed the specific needs of the population. The American founding fathers did the same; as did everyone ever who established governments anywhere.
Again, obviously, the Khulafah Rashideen had uppermost in their minds the effort to comply with the Shari’ah and achieve the best situation for the society as understood specifically by Islamic values. But, at the end of the day, the governmental system they established was man-made, not Divinely revealed. By definition, that means this system is not a religious obligation. What IS a religious obligation is the effort to comply with the Shari’ah and to achieve the best situation for society as understood by Islamic values.