Terrorism is defined by the Department of Defense as the unlawful use of force against society to coerce or intimidate governments to yield to objectives. Looking back at history we can analyze the American Revolution.
To the British the Revolutionaries were nothing more than terrorists. However, in America history classes the revolution was a freedom of oppression. My point is that what may be terrorism to some may be a liberation for others. It all depends on which side of the fence a person belongs to.
So alleged terrorists in the United States should be put through the justice system just like any other common criminal. That does not deal with the problem. Society needs to address the problems the terrorists are attempting to call to our attention. Those problems may be illegitimate but it is still important to address them.
Convicted terrorists should be given the ability to rationally voice their concerns. The justice system is more than capable of handing out a suitable punishment. It would be wrong to end a terrorists life.
That creates a sense of hostility to the cause that person was trying to bring attention to. It perpetuates violence. Violence is never going to be the answer to our problems as a species. There are many other ways of dealing with conflict.