Crankery is caused by a fundamental defect in reasoning

Casey Luskin doesn't like that evilutionists equate Intelligent Design Creationism with, well, creationism. I'm sobbing.

But in a perfect example of how cranks like using the tools of logic to make their point, and then fail, he suggests that the assertion that ID = creationism is an example of the genetic fallacy. Well, that's interesting. What's his reasoning?

Darwinian logic often contends that because a given proportion of ID proponents are creationists, ID must therefore be creationism. It's a twist on the genetic fallacy, one I like to call the Darwinist "Genesis Genetic Argument." As noted, it implies that each and every argument made by a creationist must be equivalent to arguing for full-blooded creationism. This fallacious argument is easy to defeat on logical grounds by pointing out that some ID proponents are not creationists, and in fact have been persuaded to support ID in the absence of religion. Thus something other than creationism or religion must be fundamental to the set of views underlying ID (big hint: it's the scientific data indicating real design in nature)!

First of all a big belly laugh from the "scientific data" point. But anyway, is this actually a case of the genetic fallacy? And even if it were fallacious, is it really an example of an argument of irrelevance?

Luskin links the wiki as well in his post, but it's clear he didn't read it (correctly).

The genetic fallacy is a fallacy of irrelevance where a conclusion is suggested based solely on something or someone's origin rather than its current meaning or context. This overlooks any difference to be found in the present situation, typically transferring the positive or negative esteem from the earlier context.

The fallacy therefore fails to assess the claim on its merit. The first criterion of a good argument is that the premises must have bearing on the truth or falsity of the claim in question. [1] Genetic accounts of an issue may be true, and they may help illuminate the reasons why the issue has assumed its present form, but they are irrelevant to its merits.

By origin, Luskin misreads this to mean who is promoting the argument, but that is not what is meant by the genetic fallacy, which has to do with the origin of beliefs, not who promotes them. The fallacy that he's actually looking for is poisoning the well - a kind of guilt by association ad hominem attack. A true genetic fallacy would be something along the lines of "ID comes from William Paley, who popularized the the debunked watchmaker analogy so ID is a joke."

The genetic fallacy is an attack on the origins of an argument as an irrelevant reason for it to be disbelieved. Notice, that the ID creationists frequently use the term "Darwinist" to describe evolution - an example of the genetic fallacy since the science has progressed a great deal beyond Darwin's initial observations and they like to use examples of mistakes Darwin made to try to disparage the modern forms of evolutionary biology.

Hilariously his one example to prove atheists believe in ID is Antony Flew. This is bizarre because Flew became a deist in his old age and feels there is an inadequate naturalistic explanation for the origin of life but does not reject evolution as a source of complexity - he's not an atheist or an ID believer but a theistic evolutionist - sorry Luskin.

Now, the next question, does pointing out that IDers are religious and creationists a bad argument - spoiling the well as it were? Well, not when you have the Wedge Document. Now, it would be an example of the genetic fallacy to suggest ID is wrong because it originated from this wedge strategy. If, for example, ID creationism had independent scientific merits this would be a piece of irrelevant information.

This is not the case however. ID is wrong because it fails to explain that natural world, has no data to support it and is clearly an attempt, as demonstrated by the wedge strategy, to insert creationism back into public education. It's a political/marketing movement, not a legitimate scientific movement. It is defined by promiscuous teleology, its proponents are denialists and cranks, who not only misrepresent and misunderstand evolutionary biology, but quote-mine, practice endless feats of dishonesty, and are not honest brokers in a scientific debate. ID creationism is denialism, that is why it is not a valid scientific theory.