From an authoritarian perspective, that's the genius of America's political culture. It not only finds way to obliterate the most basic individual liberties designed to safeguard citizens from consummate abuses of power (such as extinguishing the lives of citizens without due process). It actually gets its citizens to stand up and clap and even celebrate the destruction of those safeguards.
After several unsuccessful efforts to assassinate its own citizen, the U.S. succeeded today (and it was the U.S.). It almost certainly was able to find and kill Awlaki with the help of its long-time close friend President Saleh, who took a little time off from murdering his own citizens to help the U.S. murder its. The U.S. thus transformed someone who was, at best, a marginal figure into a martyr, and again showed its true face to the world. The government and media search for The Next bin Laden has undoubtedly already commenced.
What's most striking about this is not that the U.S. Government has seized and exercised exactly the power the Fifth Amendment was designed to bar ("No person shall be deprived of life without due process of law"), and did so in a way that almost certainly violates core First Amendment protections (questions that will now never be decided in a court of law). What's most amazing is that its citizens will not merely refrain from objecting, but will stand and cheer the U.S. Government's new power to assassinate their fellow citizens, far from any battlefield, literally without a shred of due process from the U.S. Government. Many will celebrate the strong, decisive, Tough President's ability to eradicate the life of Anwar al-Awlaki -- including many who just so righteously condemned those Republican audience members as so terribly barbaric and crass for cheering Governor Perry's execution of scores of serial murderers and rapists -- criminals who were at least given a trial and appeals and the other trappings of due process before being killed.