Apparently not, see U.S. v. Shabini, so an overt act requirement isn't a consequence of the 1st Amendment rule; just many laws (but not all) happen to require o

Apparently not, see U.S. v. Shabini, so an overt act requirement isn't a consequence of the 1st Amendment rule; just many laws (but not all) happen to require one. https://en.m.wikipedia.org/wiki/United_States_v._Shabani https://en.m.wikipedia.org/wiki/United_States_v._Shabani