"If there is any principle of the Constitution that more imperatively calls for attachment than any other, it is the principle of free thought — not free thought for those who agree with us but freedom for the thought that we hate."— Supreme Court Justice Oliver Wendell Holmes
There was a time in this country, back when the British were running things, that if you spoke your mind and it ticked off the wrong people, you'd soon find yourself in jail for offending the king.
Reacting to this injustice, when it was time to write the Constitution, America's founders argued for a Bill of Rights, of which the First Amendment protects the right to free speech. James Madison, the father of the Constitution, was very clear about the fact that he wrote the First Amendment to protect the minority against the majority.
What Madison meant by minority is "offensive speech."