Salon blogger and Constitutional lawyer Glenn Greenwald appeared on Democracy Now! Friday morning to voice his displeasure over the United States' killing of Anwar al-Awlaki in Yemen, a U.S. citizen who was considered a radical cleric for Al-Qaeda.

Greenwald highlighted the criticism that President George W. Bush received from the left for warrant-less wiretapping and controversial detaining. And he wondered where those voices are now to chastise President Barack Obama's decision to order a drone strike to kill Awlaki.

"Remember that there was great controversial when George Bush asserted the power to simply detain American citizens without due process or simply to eavesdrop on their conversation without warrant," he said. "Here you have something much more severe. Not eavesdropping on American citizens, not detaining them without due process, but killing them without due process. And yet many Democrats and progressives because President Obama is doing it have no problem with it and are even in favor of it."

He added: "To say that the President has the right to kill citizens without due process is to take the Constitution and to tear it into as many little pieces as you can and burn it and step on it."

WATCH: Video from Democracy Now, which appeared on September 30, 2011.

Photo: Flickr user Beverly & Pack.