You want a scary thought? Imagine a fanatic in the mold of Dick Cheney but without the vice president’s sense of humor.

In her important new book, “The Dark Side: The Inside Story of How the War on Terror Turned Into a War on American Ideals,” Jane Mayer of The New Yorker devotes a great deal of space to David Addington, Dick Cheney’s main man and the lead architect of the Bush administration’s legal strategy for the so-called war on terror.

She quotes a colleague as saying of Mr. Addington: “No one stood to his right.” Colin Powell, a veteran of many bruising battles with Mr. Cheney, was reported to have summed up Mr. Addington as follows: “He doesn’t believe in the Constitution.”