Quaide Azam Jinnah, for whom Allama Iqbal had the utmost respect and admiration, was totally against religion being a part of the Government.
Zia-ul-Haq tried to include Islam in Government and asked Ulemas to help him. What he got was a set of punitive laws including death penalty for Tauheen-e-Risalat.
Allama Iqbal himself has said:
Qaum kya cheez hai Qoumon li Imamat Kya hai - Is ko kya jaanen yeh bechaarey do Rakaat kay Imam. ["What do these Imams, who are good only for leading two Rakats (of Namaz), know about what a Nation is and what it means to be the Leader of a Nation"]
Realistically speaking, it is impossible to get a consensus among Islamic Scholars as to what an Islamic Government is.