After the murderous attacks in Paris and Copenhagen, one might wonder whether a newspaper that published the Charlie Hebdo cartoons of the Prophet Mohammad in the United States would be protected by the First Amendment. The government might make two primary arguments in support of a law prohibiting the publication of the cartoons.
First, the government might argue that the cartoons are not protected by the First Amendment because they are blasphemous. Blasphemy is defined as the act of insulting or showing contempt or lack of reverence for God or to holy persons. There is no doubt that the Charlie Hebdo cartoons of the Prophet Mohammad constitute blasphemy. (If you haven't seen them, you can find them on Google.)
During the Middle Ages, the penalty for blasphemy included death, cutting off the lips, and burning or tearing out the tongue. Thomas Aquinas argued that blasphemy was a worse sin than murder, for blasphemy "is a sin committed directly against God," whereas murder is merely "a sin against one's neighbor." In the American colonies, the Puritans punished blasphemy severely. Although the Puritans never executed anyone for the offense, they whipped, pilloried, or mutilated those found guilty of the offense.
By the time of the American Revolution, though, the idea that the government could legitimately punish an individual for disparaging religion had fallen into disrepute. The very concept was seen as incompatible with the core aspirations of a society committed to religious toleration, the disestablishment of religion, and the principle of free expression. By 1776 the law of blasphemy had come to be regarded as a "relic of a dead age."
Nonetheless, in the evangelical fervor of the Second Great Awakening in the early decades of the early 19th century, some courts in the United States aggressively punished blasphemy. In 1824, for example, Abner Updegraff was prosecuted in Pennsylvania for deriding the Bible in a public speech as "a mere fable." John Adams and Thomas Jefferson both vigorously condemned such prosecutions, calling them "a great embarrassment" to the fundamental values of the nation, but this new wave of blasphemy prosecutions continued.
When the issue finally came before the Supreme Court of the United States in 1952, the Court made clear that government in the United States cannot constitutionally restrict expression because it is blasphemous. As the court unanimously held in Burstyn v. Wilson, government "has no legitimate interest in protecting any or all religions from views distasteful to them," and it "is not the business of government in our nation to suppress real or imagined attacks upon a particular religious doctrine." Thus, although the Charlie Hebdo cartoons are surely blasphemous, that is not a constitutionally permissible basis for suppressing them.
Second, the government might argue that the publication of the Charlie Hebdo cartoons can constitutionally be prohibited because the very fact of publication creates a risk of violent response. In what circumstances can otherwise constitutionally protected expression be prohibited for this reason? Although the Supreme Court has long held that speech cannot constitutionally be restricted merely because it offends people, "invites dispute," or even "stirs people to anger," a risk of violence must be taken more seriously.
In Feiner v. New York, which was decided in 1951, the Supreme Court accepted just such an argument. Irving Feiner made an inflammatory speech on a street corner to a group of listeners. Some members of the crowd grew angry at Feiner's remarks and seemed on the verge of violence. Two police officers who were present at the scene ordered Feiner to stop speaking. When he refused, asserting his First Amendment right to continue, the officers arrested him for disturbing the peace. The Supreme Court, in a sharply divided decision, held that, in such circumstances, Feiner could constitutionally be punished.
More recently, however, the Supreme Court has moved sharply away from Feiner. What became clear to the court, particularly during the civil rights era, was that Feiner invited what came to be known as the "heckler's veto." That is, if those who object to a speaker's views know that they can effectively conscript the authority of the state to silence the speaker if they threaten violence, then the First Amendment can readily be subverted by those who seek to suppress opinions with which they disagree. This was the case, for example, when white Southerners threatened violence in response to civil rights marches, and when the residents of Skokie, Illinois, threatened violence in response to a proposed march by members of the American Nazi Party.
What the court has come to understand is that, faced with threats of violence, the government must take every possible measure to prevent the violence before it may silence the speaker. Otherwise, those who resort to violence will have the power to dictate the terms of our public debate and thereby undermine our most fundamental freedoms.
But that still leaves the question: Are there any circumstances in which the government can constitutionally silence a speaker because others threaten violence if the speaker is allowed to proceed? Consider an extreme hypothetical. Suppose ISIS threatens to behead six American hostages if anyone in the United States publishes or otherwise displays the Charlie Hebdo cartoons. Can our government, consistent with the First Amendment, make it a crime for anyone to do so? The Supreme Court has never faced such a case. What do you think?