I have often made the case that conservatives have sense of irony. Usually this takes the form of being able to argue for months that the fact we haven't captured Saddam Hussein doesn't matter, what really matters is that he is out of power, and then to declare that now that Saddam is captured the insurgency will end and peace will reign in Iraq. Someone with a sense of irony just couldn't pull that off with a strait face.
But today it turns out that not having a sense of irony means that you take an interview done on the Stephen Colbert Report seriously. Tom DeLay's legal defense fund is spreading the word that Robert Greenwald wilted under such tough questions as "Who hates America more, you or Michael Moore?"
Maybe its like a surgical thing. Can you find a sense of irony on a CAT scan and then just have the doctor cut it out?