A brief review of the act on-line indicates that aside from one indictment (Which was never further pursued) in 1803, nobody has ever been prosecuted under it. Further, if the law actually withstood a First Amendment challenge, it applies to those who communicate with foreign governments "Without authority." There is nothing in the first or second Articles of Constitution reserving such communications to the Executive Branch, nor forbidding them from the Legislative Branch. Congress, in fact, has quite a few enumerated powers in the conduct of foreign relations, and no general limit from doing anything beyond those since almost the only truly exclusive power the Executive is given in Article II is that of Commander-in-Chief of the armed forces.
Bring it DUmmtards. You won't like the result.