Not only in America but in most western countries, to be a professing communist is seen as eccentric, just a bit over the top perhaps, while professing Nazis are shunned by almost elements of the society, to the point where they try to disguise themselves as something else.
But as posters have already shown, communism is exactly as evil as Nazi style fascism and probably more evil than softer varieties such as Franco’s regime. If we took the same approach to communists that we take to Nazis, they would have no public platform.
For communism to operate in a society, there can be no free enterprise or worship of God. So it becomes necessary for the communist regime to suppress forcefully anyone who tries to do either of those activities. This is what the proclaimed communists actually want but they have no means to enforce their dogma except in their own limited circles.
If they became more organized and powerful, it would be time to take them out before they take us out.
What you are saying is that it should be illegal. What if the majority voted to elect a communist? Allende stole the election?