Though this isn't written by me, it should answer some stuff:
The Islamic system and democracy are similar :
1. Maximum freedom for the people - freedom of religion, freedom of expression, freedom to travel, and freedom of economy. (No different from democracy).
[2:256] There shall be no compulsion in religion: the right way is now distinct from the wrong way. Anyone who denounces the devil and believes in GOD has grasped the strongest bond; one that never breaks. GOD is Hearer, Omniscient.
[10:99] Had your Lord willed, all the people on earth would have believed. Do you want to force the people to become believers?
[88:21] You shall remind, for your mission is to deliver this reminder.
[88:22] You have no power over them.
2. Guaranteed human rights for all the people, regardless of their race, color, creed, social status, financial situation, or political affiliation (Again. no different from democracy).
[5:8] O you who believe, you shall be absolutely equitable, and observe GOD, when you serve as witnesses. Do not be provoked by your conflicts with some people into committing injustice. You shall be absolutely equitable, for it is more righteous. You shall observe GOD. GOD is fully Cognizant of everything you do.
[49:13] O people, we created you from the same male and female, and rendered you distinct peoples and tribes, that you may recognize one another. The best among you in the sight of GOD is the most righteous. GOD is Omniscient, Cognizant.
3. An economic system based on constant circulation of wealth, no usury(Usury means excessive interest), and productive investment. Non-productive economy such as gambling, lottery, and high interest loans are not permitted. (Slightly different)
[2:275] Those who charge usury are in the same position as those controlled by the devil's influence. This is because they claim that usury is the same as commerce. However, GOD permits commerce, and prohibits usury. Thus, whoever heeds this commandment from his Lord, and refrains from usury, he may keep his past earnings, and his judgment rests with GOD. As for those who persist in usury, they incur Hell, wherein they abide forever.
[2:276] GOD condemns usury, and blesses charities. GOD dislikes every disbeliever, guilty.
4. Social justice for all.(Again. no different from democracy).
[2:215] They ask you about giving: say, "The charity you give shall go to the parents, the relatives, the orphans, the poor, and the traveling alien." Any good you do, GOD is fully aware thereof.
[70:24] Part of their money is set aside.
[70:25] For the poor and the needy.
5. A political system that is based on unanimous consensus. Through mutual consultation and freedom of expression, one side of any given issue convinces all participants in the discussion. The end result is a unanimous agreement, not the opinion of a 51% majority rammed down the throat of the 49% minority.(Slightly different perhaps).
[42:38] They respond to their Lord by observing the Contact Prayers (Salat). Their affairs are decided after due consultation among themselves, and from our provisions to them they give (to charity).
7. Maximum regard for people's lives and properties.(Again. no different from democracy).
among other things.