A Jury Trial

The Constitution guarantees the rights of citizens to a jury trial when they are accused of a criminal offense. A jury can decide both matters of law and fact even though the courts have greatly restricted a jury's ability to decide matters of law. A jury can however return a verdict of not guilty when they disagree with a judge's instructions on matters of law. This puts a lot of power in the hands of the citizens.

A sitting President can trump this power by detaining a citizen and refusing them their civil rights to a fair and speedy trial. The problem is that when the President does this he has acted illegally and violated the rights of the accused.

Treason is no different than any other criminal offense. The accused citizen has the right to due process of law. The abuse and denial of those rights by the Executive is an illegal and impeachable offense.