The founders weren't picky. Trial by jury; trial by fire; rock, paper, scissors--who cares? "Due
process" just means there is a process that you do.... First, the president meets with his
advisers and decides who he can kill. Then, he kills them. The president has had these powers ever since Congress passed the Authorization for the Use of Force bill, after long and careful consideration, three days after 9/11.
We're at war with terror. Therefore, the president can blow up any American citizen he chooses until we win the war, by defeating the idea of being afraid.