The correct answer is the 1st Amendment
The US Constitution protects even the most offensive and controversial speech of repression government, and allows regulation of expression only under certain limited and restricted circumstances. The American system is built on top of idea that free exchange and open minded encourages understanding, promotes the search for the truth and allows the refutation of falsehoods. The states United believe, and experience has shown, that the best way to counter an offensive speech is not by means of regulation, but with more speech.
