Intelligent Design is the most recent form of creationism, but its roots are very old. Intelligent Design is based upon the idea that we can deduce the existence of God from the existence of design in the universe, a view popularized by William Paley's Watchmaker Analogy in his 1802 book Natural Theology. According to Paley, if you came across a watch on a beach, you would not assume that it had assembled due to chance. Instead, its design implies that it was designed by a watchmaker. The same, he argued, is true for the universe — and this is the basis for Intelligent Design Creationism today.
Understanding the critiques of evolution that come from Intelligent Design is critical to understanding Intelligent Design itself. This is because Intelligent Design ultimately doesn't amount to much more than an assault on naturalistic, materialistic
evolution. Intelligent Design was created to find a foundation for attacking evolution that sounded more rational than traditional creationism, but it hasn't grown beyond most of the fundamental problems behind all forms of creationism.
One of the most significant ways in which Intelligent Design is revealed as being political and ideological rather than scientific is by the methods used by Intelligent Design apologists. In science, researchers are expected to provide substantial evidence in support of their claims and to show how their explanations do a better job than the alternatives. Intelligent Design, in contrast, invests all its time attacking evolution and little to no time coming up with anything better.
Intelligent Design is, like all other creationist movements, more about politics and religion than about science. Where Intelligent Design differs is that it was originally and deliberately conceived in explicitly political terms whereas earlier creationist movements tended to acquire political goals and principles over time. This is very important to understand because it reveals as false the pretensions of Intelligent Design apologists that they are involved in a scientific enterprise.