Thread on Trump's latest empty threat.

1/The only way Trump can designate Antifa (or any other domestic group) terrorist is by tweet--and that has no legal consequences. No law authorizes designation of domestic "terrorist" groups, only foreign terrorist groups.

2/And the Supreme Court has held that the Constitution prohibits Congress from banning organizations that engage in both legal and illegal activities, or punishing people for associating with them. It's called "guilt by association," and it violates the First Amendment.

3/We tried this before. Congress sought to make it a crime to be a member of the Communist Party. The Supreme Court ruled that individuals can't be punished for membership or support, but only if they "specifically intend" to further a group's illegal activity.