Many of you might be surprised to learn that a Cabinet level position was the intent long before September 11. The US Commission on National Security/21 Century recommended it over a year ago.
See this article
Here is a link to the Commission's homepage. http://www.nssg.gov I believe the Cabinet level position is recommended in the third report.
Also, some of you might find my recent post on the Commission of interest. It is here. Post #52 (second one down).