This is interesting...

From Toward Freedom (digg mirror):

Public Law 109-364, or the "John Warner Defense Authorization Act of 2007" (H.R.5122) (2), which was signed by the commander in chief on October 17th, 2006, in a private Oval Office ceremony, allows the President to declare a "public emergency" and station troops anywhere in America and take control of state-based National Guard units without the consent of the governor or local authorities, in order to "suppress public disorder."

This could be a tool for dictatorship or a method to prevent another post-Katrina chaos situation, but I don't think I approve. First habeus corpus... now Posse Comitatus.

via metafilter