Charles Krauthammer is responsible for the identification of a mental illness that afflicts the left almost without exception, and his column for today describes a related condition, witnessed recently in full bloom when Dick Cheney’s heart condition was in the news: Bush Derangement Syndrome, Cheney Variant.

WASHINGTON — “What is wrong with Dick Cheney?” asks Michelle Cottle in the inaugural issue of the newly relaunched New Republic. She then spends the next 2,000 words marshaling evidence suggesting that his cardiac disease has left him demented and mentally disordered.

The charming part of this not-to-be-missed article (titled ”Heart of Darkness,“ no less) is that it is framed as an exercise in compassion. Since she knows that the only way for her New Republic readers to understand Cheney is that he is evil — ”next time you see Cheney behaving oddly, don’t automatically assume that he’s a bad man,” she advises — surely the generous thing for a liberal to do is write him off as simply nuts. In the wonderland of liberalism, Cottle is trying to make the case for Cheney by offering him the insanity defense.

She doesn’t seem to understand that showing how circulatory problems can affect the brain proves nothing unless you first show the existence of a psychiatric disorder. Yet Cottle offers nothing in Cheney’s presenting symptoms or behavior to justify a psychiatric diagnosis of any kind, let alone dementia.