I'm not supporting Obama's policy but I don't think this is as evil as everyone is making it out to be. Our country is theoretically "at war" with Al Quada as an organization (whether that makes any sense is a whole other tangent). During World War II, plenty of German-American citizens living in the US flue back to Germany and fought against American forces.
So now a theoretically declared war against a poorly defined group of individuals is the same as a congressional deceleration of war against a sovereign nation?
We didn't need due process to kill them on the battlefield. Whether you're an American citizen or not, if you're on foreign territory and pose a threat to our armed forces, there's not a large legal barrier to killing you.
In a genuine time of war exceptions to due process are made. We are not at war. We are not at war with Yemen, yet American citizen Anwar al-Aulaqi was killed there by a drone strike because of the memo you support. He was considered to be a high ranking al-Qaeda agent.
Two-weeks later is 16 year old son, Abdulrahman al-Aulaqi, was killed in similar air-strike. He too was an American citizen. He was traveling with a high ranking al-Qaeda agent, who was the actual target of the air strike. The strike was 'OKed" because Abdulrahman al-Aulaqi was considered to be a "military-age male."
We are not at war. As a country we have lost our way. A secret memo is released and we justify why it is OK to kill Americans abroad without any due-process. We claim we want transparency, and yet accept secret memos. We accept killing of foreign men, woman, and child in countries in which we are not at war, because 'civilian causalities are low'.
The President says "If We Can Just Save One Child..." we should give up are constitutional rights. According the Bureau of Investigative Journalism some 175 children have been killed by the drone program. What about saving just one of those lives? No, lets all attack the Bill of Rights when American children die, but programs that operate on the fringe of legality are OK because foreign children are not afforded the same protections.
Does our hypocrisy as a country have any limits? Do we ever look around, and say WTF is wrong with us. Do we not believe our rights to be natural, and our government is unique in that it recognizes and protects those natural rights? And if we believe these rights natural are they not natural to all people? If natural to all, then shouldn't our government, a government that respects natural rights, also at a minimum respect the natural rights of people in foreign countries, US citizen or otherwise? Or are the principles upon which the country was founded, tied only to the earth on which it is rooted?