U.S. Senator Lindsey Graham: “I think, anyone who’s on the Terrorist Watch List should not lose their Second Amendment right without the ability to challenge that determination. I think, Senator Kennedy was on the Terrorist Watch List. There’ve been people come up on the watch list. I did not want to make that a — the basis to take someone’s Second Amendment rights away. What I would suggest, is that if you come up on the Terrorist Watch List, you have the ability to say, ‘No, I’m not a terrorist.’ And that would be the proper way to do that.”
So you should be able to challenge your inclusion on that list when it comes to buying guns, but when the federal government wants to take you into custody on that basis, no challenges.