President's Power to Detain

Does the President have the right to detain a U.S. citizen indefinitely? The Supreme Court has agreed to hear the case concerning Ali al-Marri to decide. The thought of a U.S. citizen being detained indefinitely is repulsive. It has always be the right of Americans to have a speedy trail as well as a representative. Are there any circumstances that could legally change that constitutional right? The war on terror has been a confusing one and the politics surrounding it are extremely murky. The President has taken a more assertive role as the executive of this nation but has he taken it too far. Many would say yes. I am undecided. However I do believe the President does not have the right to detain an American citizen for as long as he likes. The founders gave the Executive Branch of the government limited powers for a reason. The President's power as Commander in Chief does include detaining persons of national threat in times of war however the person in question should be charged with a crime and sent to the judicial system. It should not be within the President's power to be judge and jury, which is essentially what is happening in this case. This topic is a sensitive one but I am convinced that the President's power does not include indefinite detention of an American citizen. How can the Presdident have the right to take away our rights as Americans? It is not constitutional for the President to detain a U.S. Citizen without charging them with a crime and trying them for that crime.