"Our Constitution is great. But it doesn't necessarily give us the right to commit suicide, okay?"

So said Donald Trump on the July 24 edition of Meet the Press, concerning his intention to restrict immigration into the United States from areas with high levels of terrorism. In other recent interviews Trump has said the same thing, using almost the same words, including "suicide," which does rather catch your attention.

Trump seems to have memorized the point, and Josh Blackman, the law professor and blogger, has noticed its similarity to what Justice Jackson famously wrote in his dissent in Terminiello v. City of Chicago, a 1949 case vindicating free speech rights. Jackson worried that if the Supreme Court does not "temper its doctrinaire logic with a little practical wisdom, it will convert the constitutional Bill of Rights into a suicide pact." Someone might have conveyed to Trump the essence of what Jackson said, perhaps even using the justice's actual words. That's a more plausible explanation for how he came up with the word "suicide" than that one night he read Terminiello in a casebook.

In Terminiello a rogue Catholic priest named Arthur Terminiello gave a fiercely anti-Communist speech to the Christian Veterans of America, which was meeting in Chicago. He criticized, by no means gently, various racial groups. A crowd of 800 collected in an auditorium to hear his speech while roughly 1,000 stood outside to protest it. Riots ensued, and the police were unable to keep order. Terminiello was charged with violating a Chicago ordinance banning speech that "stirs the public to anger, invites dispute, brings about a condition of unrest, or creates a disturbance." He was convicted, but the Supreme Court overturned the ruling, having concluded that the First Amendment protected Terminiello's speech.

Jackson granted that the First Amendment protects the expression of ideas, but not absolutely, nor in all circumstances, without regard to the danger it may create. For Jackson, the majority failed to grasp the chaotic and violent nature of the scene that night in Chicago. Here is the passage (concluding his opinion) in which Jackson used the term "suicide pact":

This Court has gone far toward accepting the doctrine that civil liberty means the removal of all restraints from these crowds and that all local attempts to maintain order are impairments of the liberty of the citizen. The choice is not between order and liberty. It is between liberty with order and anarchy without either. There is a danger that, if the court does not temper its doctrinaire logic with a little practical wisdom, it will convert the constitutional bill of rights into a suicide pact.

Terminiello was not about immigration, the subject of Trump's concern. Trump wants an immigration policy that would prevent terrorists from entering the country and fighting us on our own ground—in other words, from within. At first he said he would ban all Muslim immigrants. Then he said he would impose a temporary ban on all Muslim immigrants. Recently he has said he would ban all immigrants from certain "territories" or "areas"—"terror states" and "terror nations," as he calls them.

If Trump is elected and enacts his immigration policy, it may well attract lawsuits from parties claiming to have suffered some injury or other as a result of its implementation. While there is no right to immigrate into America, other claims might be litigated, such as that a Syrian American's business model requires him to hire Syrians, which means Syrian immigrants, and that the new policy unlawfully prevents him from doing that.

Trump is saying, in effect, that litigation over such issues should not result in decisions that disable the government from doing its first job of defending and protecting the country. The Constitution, he is saying, is great but it cannot mean that we must be defenseless against terrorist attacks at home.

For Trump, then, the Constitution isn't a suicide pact, and liberty must have limits. But this story about Trump's immigration policy ends with Terminiello, and in particular with the fact that Jackson wanted to impose limits on the free speech rights of an inactive priest trying to whip a crowd up into a violent frenzy. The irony here is that the Terminiello rally sounds a lot like a Trump rally. And because it does, maybe Trump should feel lucky that Jackson's position isn't the law. If it were, then Trump rallies might have to be shut down—in order to prevent our suicide!