I'd like to just go on the record about this notion of stripping Americans of their citizenship for joining a terrorist organization. This is a terrible idea that has, as things usually do, steadily gotten worse the more Congress has messed with it.
The proposal is completely pointless because, even if State declares that you have forfeited your citizenship, you have every right to challenge the decision in court. The sole and only benefit to the United States of stripping someone's citizenship would be to avoid going to court, where they would have to introduce intelligence into the public record, etc. This law offers no hope of obtaining that benefit. State would have to prove in court not only that you were a member of a terrorist organization, but that you joined with the intention of renouncing your citizenship and its advantages.
If you can prove in court that someone is guilty of joining a terrorist organization to wage war against the United States, and if you're going to commit to going to court anyway, why on earth would you want to strip them of their citizenship? All that does is introduce another question that the courts have to resolve before they can be executed. The proper thing to say is not, "This person is not an American," but rather, "This American is a traitor."
This is fighting on the wrong hill. We have nothing whatsoever to gain from establishing that traitors aren't good enough to be Americans. Rather we should say: Even traitors are good enough to die for their country.
Let's help them along. All this does is give them an excuse to drag out their legal defense another decade or two.