News reports indicate that President Trump intends to try to use emergency powers to appropriate money and seize property for his border wall, because Congress was unwilling to give him more than a small fraction of the funds he wanted. In several previous op eds and blog posts, I explained why he lacks the legal authority to do that, and why it would set a dangerous precedent if he managed to get away with it.

In a January op ed in USA Today, I discussed the relevant legal issues, and the potential for setting a dangerous precedent:

Poorly drafted laws give the president a wide range of easily abused emergency powers. Even if he can declare a "national emergency," however, that does not mean he can use it to pay for and build a wall…. Some point to 10 U.S.C. 2808 and 33 U.S.C. 2293 as possible justifications. But Section 2808 states that, during a "national emergency" that "requires the use of the armed forces," the president can reallocate defense funds to "undertake military construction projects … that are necessary to support such use of the armed forces." No threat posed by undocumented immigration "requires the use of the armed forces," and it is hard to see why a wall is "necessary to support such use." In fact, as Yale Law School professor Bruce Ackerman explains, longstanding laws bar the use of troops for domestic law enforcement (including enforcing immigration law). Section 2293 also only applies to a war or emergency that "requires or may require use of the armed forces." Another federal law allows the military to condemn property for various purposes, such as "fortifications." But that only extends to projects for which funding has been appropriated by Congress…. Even if the president can use emergency powers to get funds, that does not mean he can seize property by eminent domain. The Supreme Court has long held that the use of eminent domain must be expressly authorized by law. No emergency law expressly permit the use of eminent domain for border walls not otherwise authorized by Congress. Building Trump's wall requires using eminent domain on a massive scale. A third of the needed land is owned by the federal government. The rest would have to be taken from private owners, Native American tribes and state governments, many of whom are unlikely to sell voluntarily. The result would be one of the largest federal condemnations in modern U.S. history…. If Trump succeeds in using emergency powers to build the wall and seize property through eminent domain, future presidents could exploit this dangerous precedent. They, too, could declare a "national emergency," and then divert military funds and take private property without congressional authorization. Republicans who cheer Trump now will regret it if the next Democratic president uses the same powers to declare that climate change is a "national emergency" and then allocate funds and take land for the gigantic "Green New Deal" program many progressives advocate. Climate change is a more plausible menace to national security than undocumented immigration. If Trump succeeds, presidents could use the same ploy almost any time they want funds or seek to condemn private property for purposes Congress has not authorized, so long as there is some vague security pretext.

While Trump deserves to lose in litigation over the legality of building the wall by using emergency powers, the outcome of such litigation is somewhat uncertain. Administration lawyers may have come up with creative legal arguments that outside observers have not foreseen. In addition, courts all too often give presidents undue deference on security and immigration issues.

I am far from the only observer to warn against the dangers of using emergency powers in this way. Nor is concern about the risk limited to those (like myself) who oppose the wall on grounds of morality and policy. A number of principled conservatives who are far more supportive of the wall than I am nonetheless warn against the dangerous precedent that would be created if Trump succeeds in using emergency powers here. I discuss their views here.

If Trump's emergency power strategy succeeds, it would also threaten the property rights of hundreds or even thousands of people who own property near the border. Many are likely to have their land seized by the federal government through the use of the power of eminent domain. I discuss the harm likely to be caused by that in this Washington Post op ed, written last month:

Trump cannot acquire the land he needs without forcibly displacing large numbers of property owners by using eminent domain. That inevitably threatens the property rights of hundreds, perhaps thousands, of Americans. Less than one-third of the needed land is currently owned by the federal government. The rest — as much as 1,300 miles — is held by private owners, Native American tribes and state governments, many of whom are unlikely to sell voluntarily. Even if the wall does not cover the full 2,000 miles because it excludes some areas, such as those that have "natural" barriers, many property owners will have to be displaced. There is no way to build an extensive continuous wall without that…. To get that land, the government would have to resort to eminent domain: a power that allows the state to seize property from unwilling owners. The result would be one of the largest federal condemnations in modern U.S. history. In Texas alone, there are some 4,900 parcels of privately owned land within 500 feet of the probable route of the wall…. Under Supreme Court precedent, owners of condemned property are entitled to "fair market value" compensation: roughly, the price the land would go for if sold on the open market. But studies show that owners often don't get the compensation that the law requires. That is particularly true of those who are poor or lack legal sophistication. Government officials often shortchange such people by using pressure tactics to get them to sell at below-market prices. Such abuses were common in takings for previous, much smaller border barriers…. Even when owners do secure market-value compensation, that often fails to fully offset their losses. Many understandably value their property above its market value. Often, that's why they hold on to it in the first place. Consider, for example, longtime homeowners or businesspeople who have developed close ties with customers and neighbors in a community. Those losses remain largely uncompensated….

I will likely have more to say about Trump's effort to use an emergency declaration to build the wall as we learn more about his exact plans. The issue will almost certainly wind up in court, and could well result in a prolonged legal battle.