Until this week, the president?s personal authority to use America?s military might was subject to two opposite historical trends. On the one hand, there is the biggest scandal in constitutional law: the gradual disappearance of the congressional Declaration of War.
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In terms of the power he now claims, without significant challenge, George W. Bush is now the closest thing in a long time to dictator of the world.

Sovereign authority - By Michael Kinsley - Slate.com