As suggested below, Cheney's efforts to expand executive power predate his current position as vice-president. This article points out how his minority report on the Iran-Contra scandal (which he didn't consider a scandal at all) introduces arguments that have been expanded more recently.
It also suggests that he thought Congress overstepped in its investigations of Richard Nixon. His career follows an interesting path. He works in Nixon and Ford's White House, where he seeks to expand presidential powers, and then spends time in Congress where he attempts to do the same, but this time by undermining Congress from within. Now as vice-president he further expands those powers.
What focus. One wonders what motivates him.
