Life During Wartime, continued
What Constitutionally-enumerated powers were used to outlaw, disarm, or even identify the Ku Klux Klan?

What was used for probable cause to go after them (or was probable cause the "thirteenth floor" then, like the Second Amendment has been since NFA '36)? Is there anything here that would be of use to us in a Constitutionally permissible pursuit of islamists in the United States?

Update: The KKK wasn't outlawed or disarmed, was it? Maybe this line of inquiry is a non-starter. Don't worry, I can't quit my day job. Literally. Can't.