Anyone may believe all sorts of things in his own mind;but societies set limits on what actions a person may take.
You would allow sedition, treason, and terrorism to spread by allowing them to claim freedom.American freedom was never intended to protect those who act to destroy the country.
We can and should outlaw and prosecute all acts of violence,intimidation,and conspiracy done on behalf of those belief systems.
Exactly. And Americans were free to be Communist, free to associate with Communists, free to gather among like minded Communists and form organizations (that were promptly infiltrated by the FBI).
They are free to believe any fool thing they want, but they are watched (due to their anti-American ideology, they warrant and receive special scrutiny) and any criminal actions ARE prosecuted.
But to forbid Americans to build or organize around a religion or ideology dependent upon the laws of a despotic tyranny? Absolutely ridiculous!