I don't know exactly how to explain Dick Cheney. We had an editorial board meeting with him early in the Bush presidency (but after 9/11) and he is obviously quite intelligent and even has a sense of humor, though it's a little dark. But his obsession with secrecy and power seems to be all-consuming.
"Miniver loved the Medici
Albeit he had never seen one.
He would have sinned incessantly
Could he have been one." -- Edwin Arlington Robinson
The best explanation I've heard is that the lesson he took from Watergate was not that it was an egregious abuse of power but that it was a darned shame because it had the effect of undermining the powers of the president/presidency, which he apparently sees as almost limitless. The president should not only be powerful, he should be able to keep almost everything he want to secret and operater in the shadows. Not for our Miniver any foolishness about transparency or accountability to the mere people. Dick Cheney has spent the rest of his life trying to rebuild presidential power and in Dubya he seemed to have a willing student. But the upshot of their efforts might well be to discredit the idea of expansive presidential power almost as much as Watergate did -- or more.
Here's just one example. Four years ago Bush issued an executive order on the handling of classified material. All executive-branch offices are supposed to report how they handle such material to an office in the National Archives and Records Adminsitration. Cheney's office has not only not done so, it tried to get the office abolished.
His excuse? The office of the vice president is not strictly part of the executive branch, since the vice president is also president of the Senate. It's quite a stretch, but Cheney is an old hand at stretching the rules, including the laws and international conventions on torture.
The Washington Post has started a series on Cheney's love of power, secrecy and stretching the rules -- probably one of those mulltipart series newspapers put together when they're thinking about Pulitzers. Nonetheless, it looks to be worth reading.