President Joe Biden has issued an executive order that shuts down the southern U.S. border to all but a few asylum-seekers — a move reminiscent of former President Donald Trump’s efforts, which were blocked by the federal courts.The political motivation is obvious: Immigration has become a serious worry for Biden in the presidential race, and Republicans in Congress have blocked bipartisan legislation that would have provided much-needed funding for border control and processing asylum applications.Yet Biden’s order is both morally and legally troubling. If implemented, it would deny asylum to people who legally deserve it — those who would be persecuted in their countries of origin. And the order is almost certainly unlawful under the standards imposed by the courts on Trump’s similar orders. If federal judges are consistent, they will block Biden’s order from going into effect.That’s the likely outcome. And it raises an important ethical problem at the intersection of politics and law: When is it justified for the executive branch to issue an order it believes will win some political points, but knows (or hopes) will be struck down by the judiciary? This cynical approach undermines the rule of law.The legal issues are technical but can be summarized roughly as follows. Under current law, non-citizens (called “aliens” in legalese) who come to the U.S. and seek asylum cannot simply be sent home. They must be given an opportunity to make the case that, if sent home, they would be subject to persecution “on account of race, religion, nationality, membership in a particular social group, or political opinion.”Currently, federal law entitles them to a quick screening interview. Between 2014 and 2019, 83% of asylum-seekers passed this hurdle. In 2023, however, the Biden administration made it harder to get through the interview, and the number who pass that stage has since dropped to 52%. But, like the Trump administration before it, the Biden administration has now taken action to get the number a lot lower – essentially to zero.Trump’s executive actions on the border relied on section 212(f) of the Immigration and Nationality Act, which says the president can suspend entry of any class of aliens if he determines their entry would be “detrimental to the interests of the United States.” To oversimplify a bit, the federal courts rejected Trump’s claim that this provision let him shut down the border to asylum applicants.Other statutes say that people who have ...