By claiming such systems to be "irreducibly complex", Behe is demonstrating a basic ignorance of how evolution works.
In effect, Behe's "designer" is nothing more than the old "God of the gaps", in which anything we do not yet understand is attributed to divine action. The problem with this viewpoint is that, as we understand more and more, there is continually less and less for the God of the gaps (or Behe's "designer"
In addition, neither Behe nor anyone else can scientifically say to us anything about their "intelligent designer". What exactly is the scientific theory of intelligent design? According to this scientific theory of intelligent design, what is the intelligent designer? Is it a space alien? A god or goddess? The Great Pumpkin? Time-traveling human bioengineers from the future? What, precisely, does the scientific theory of intelligent design postulate that the intelligent designer(s) do to accomplish these designs? What mechanisms does it use, according to the scientific theory of intelligent design, and where can we see these mechanisms operating today? What scientific data or evidence shows that there is only one "intelligent designer" and not, say, ten or fifty or a hundred of them? Intelligent design "theory" is utterly silent on all these questions. Indeed, intelligent design "theory" cannot even make an attempt to answer these questions, since the answers would reveal instantly the religious basis for this "theory", and would guarantee that "intelligent design theory" would never see the isndie of a public school classroom. For this reason, most "intelligent design theorists" go through all sorts of intellectual contortions to avoid explaining exactly who or what their "intelligent designer" is.
< Another question that immediately leaps to mind is "Who designed the Intelligent Designer"? Behe (and the creationists) will of course answer that the "Intelligent Designer always existed". Any "intelligent designer" that exists outside the laws of nature is, however, by definition, God, and God is by definition religious in nature. It is not scientific, it cannot be tested and it cannot be falsified. It is based solely and only on the creationist religious belief that God designed and created life by divine fiat.
The creationists are of course entirely welcome to this religious assumption if they like it. But they aren't saying anything scientific, and as science, "intelligent design theory" is utterly useless. It makes no testible predictions. It answers no scientific questions. It opens no new area sof investigation, and enables no new experiments that could not be performed without it. In fact, there has not been any scientific discovery, of any note, in any area of science, made in the last 20 years as the result of "intelligent design theory". "Intelligent design theory", it appears, consists solely of the assertions (1) we think there is an Intelligent Designer, (2) we don't know what it is, (3) we don't know what it does, (4) we don't know how it does it, and (5) we don't know how to go about answering any of those questions, but (6) we want you to teach about it anyway. Intelligent design "theory" is religious apologetics, nothing more and nothing less.
It is not, then, surprising that the Intelligent Design movement has lost where it has attempted to paint itself as "science". In 2002, the Discovery Institute led an effort in Ohio to modify the state's science education standards to include "intelligent design theory" as an "alternative" to evolution. State officials did insert an addendum ino the state's science education standards that read: ""Describe how scientists continue to investigate and critically analyze aspects of evolutionary theory." The intention of this was to encourage discussion of cutting-edge issues in modern biology, such as the debate over whether birds are descended from dinosaurs or from other archosaurs. The IDer's assumption that this would allow them to present their "alternative science", however, was dashed by another addendum: "The intent of this indicator does not mandate the teaching or testing of intelligent design."
In the face of its Ohio defeat, the ID movement changed its strategy once again, and now only rarely tries to present "intelligent design theory" as a "scientific alternative". Instead, ID advocates now clamor for "teaching the controversy", and argue in favor of requiring schools to teach "the evidence againsty evolution" without specifying what that evidence is or what scientific alternative they want to offer. Alas for the IDers, when this tactic was put into practice in Texas, in November 2003, they lost just as resoundingly. An effort to require Texas science textbooks to modify their treatment of evolution was rejected by the state textbook committee.