The Logan Act[1] might be a place to start, though it's more often used as a theatrical threat, in the same way that people accuse each other of treason wheneve

The Logan Act[1] might be a place to start, though it's more often used as a theatrical threat, in the same way that people accuse each other of treason whenever they disagree. [1]http://www.law.cornell.edu/uscode/text/18/953 http://www.law.cornell.edu/uscode/text/18/953