New Civitas Outlook Essay: Four Questions and Few Answers About the Invasion Clause

I have written several somewhat tentative posts on the Invasion Clause. This is an issue on which the courts have not substantially opined, and there is very little settled precedent In my latest essay for Civitas Outlook, I raise four questions for which there are few answers.

Here is the introduction:

On inauguration day, President Trump signed a proclamation "guaranteeing the states protection against invasion." Trump determined that the federal government had "failed in fulfilling [its] obligation to the States" at the southern border and would "take measures to fulfill its obligation to the States." In 2024, Texas Governor Greg Abbott also declared that there was an invasion at the southern border. Most critics saw these actions as partisan statements with no actual legal effect. I disagree. There are important constitutional ramifications to declaring an invasion. If there is an invasion, both the federal government and the states receive additional war powers to repel that invasion. Federal laws that conflict with those war powers may give way. Moreover, the children of invaders may not be entitled to citizenship at birth.

The concept of an invasion may seem obscure today, but it was certainly on the Framers' minds. Four separate clauses of the Constitution reference invasion. Some scholars and judges argue these issues are open-and-shut. They claim that an invasion must be hostile, peaceful migrants cannot be invaders, and the courts have the power to second-guess the president's proclamation. I am not so sure. Here, I will address four questions with few definitive and settled answers. First, what is an invasion? Second, who can declare an invasion? Third, what happens to other federal laws during an invasion? And fourth, do the children of invaders receive birthright citizenship? Once again, Trump has brought long-forgotten provisions of the Constitution to the arena and forced our polity to grapple with whether this President should be treated any differently from all other presidents.

And the conclusion:

Ultimately, I am certain about one principle, which I repeated through Trump's first term, and I will repeat for four more years. Whatever the meaning of the invasion clause, the answer cannot turn on the unprecedented nature of the Trump presidency. These legal questions should have an answer that does not depend on Trump. Either the President has the power to declare an invasion, or he does not. Either the state has the power to declare an invasion, or it does not. Either the judiciary has the power to second-guess a federal declaration of an invasion, or it does not. Either the children of invaders receive birthright citizenship, or they do not. The answer to those questions has to be the same in 1788, 1868, or 2025. I've raised four questions here, and I do not think many clear and settled answers exist. But in any event, these issues cannot decisively cut against the position taken by President Trump and Texas.