One of the excuses for ignoring the emphatic Shari‘ah obligation of re-instituting the Caliphate is the claim that it is an impossible dream which cannot be realised. According to this argument, the Caliphate is deemed to be a Utopia which present-day Muslims cannot bring to fruition. This is despite the fact that the Caliphate previously existed for several centuries and succeeded in spreading Islam to many lands.
Imam Ghazali on the ‘Ulamā’ of the Hereafter, the Teachers of Falsehood and Avoiding Rulers
“Another characteristic expected of the scholar is that he keeps away from the rulers and, as long as he can help it, not to come near them at all, and rather avoid their company despite any efforts on their part to seek him out, because the world is attractive and inviting while the power to dispense with its riches is in their hands. To associate with them, therefore, would necessarily involve the scholar in seeking their approval and winning their hearts, although they are unjust and unrighteous. It is, then, the duty of every religious man to censor them by exposing their tyranny and decrying their practices. For he who frequents their palaces will either seek their favour and consequently forget the blessings which Allah has bestowed upon him, or hold his peace and allow their misdeeds to go uncensored, thereby courting their favour.”