Assistant Attorney General, Office of Legal Counsel during Bush's term:
http://www.lawfareblog.com/2013/03/on-senator-pauls-filibuster
In general Senator Paul and others falsely maintained that the Obama administration has implied that it has authority to use a drone to kill a U.S. citizen inside the United States who is not engaged in combat and does not present an imminent threat and who is simply (a hypo they keep using) “sitting quietly in a café peaceably enjoying breakfast.” Senator Paul also claims that the administration’s position on homeland use of force has no legal limits and amounts to martial law. Along the way, Senator Paul is painting a misleadingly very unattractive picture of the circumstances in which the United States uses drones abroad in words that will now be played around the world as credible statements of U.S. policy.
http://www.lawfareblog.com/2013/03/on-senator-pauls-filibuster