IF YOU could design people in a laboratory to be an adornment to America they would look like the recipients of DACA. Deferred Action for Childhood Arrivals, an executive action issued in 2012 by Barack Obama to protect most of those who were brought to the country as children from deportation, covers about 800,000 people. They are a high-achieving lot. More than 90% of those now aged over 25 are employed; they create businesses at twice the rate of the public as a whole; many have spouses and children who are citizens. They are American in every sense bar the bureaucratic one.

Correcting that ought to be about as hard politically as declaring a new public holiday. Instead, there is a good chance that Congress will return them to their prior limbo, or worse. Recipients of DACA were obliged to give their addresses to the federal government, which is charged with immigration enforcement, making it considerably easier to round them up now. After the Trump administration announced that it would end the programme in six months’ time, and called on Congress to pass a bill to replace it, the White House issued a set of talking points which suggested that Immigration and Customs Enforcement would find this personal information, given in exchange for shelter, very useful.

Both Mr Trump and Jeff Sessions, his attorney-general, presented the decision to end DACA as a victory for the rule of law (see article). There is something to this. Mr Obama said publicly that he doubted he had the authority to protect people from the enforcement of immigration laws passed by Congress and signed by previous presidents. Then he decided that, in fact, he did. Mr Trump’s administration thus faced having to defend an executive action by its predecessor from a legal challenge by several Republican attorneys-general—a challenge that the administration might lose in the Supreme Court at the hands of his own nominee, Neil Gorsuch. With that prospect, Mr Trump pushed the decision back to Congress.

But the choice on DACA is not between the rule of law and rule by presidential edict. It is between two different types of legal failure—executive actions that are possibly unconstitutional and a set of immigration laws that are definitely impossible to enforce. There are about 11m people in the country illegally, many of whom arrived decades ago. America already spends a huge amount on deportation—more than on the FBI, DEA, Secret Service, US Marshals and Bureau of Alcohol, Tobacco and Firearms, combined. At current deportation rates it would take over 40 years to expel them all. Congress has not willed the means to make this happen and would not want to face the consequences of doing so. The collective failure to say this on the part of the Republicans, who control both houses of Congress, is a giant exercise in ignoring reality. “Useless laws weaken necessary laws,” wrote Montesquieu, whose work the authors of the constitution consulted frequently. That is a fair description of the effect of America’s immigration laws, whose uselessness results in lawbreaking becoming routine.

Deferred action

The solution is for Congress to write DACA, or something like it, into law. Yet the long-running saga over DACA and its recipients, whose average age is now 25, has been another sign that Congress’s default setting is to inaction. Mr Obama issued his executive action after years of waiting for Congress to write legislation. Congressmen ducked the decision, leading the president to take it unilaterally, on questionable authority.

Mr Trump’s call on Congress to act may set up a repeat of this cycle. The programme expires in six months’ time, at which point many Republican congressmen will face primaries. They will be confronted by challengers denouncing anyone who supports such legislation as being pro-immigration-amnesty and too unpatriotic to put real Americans first, a Republican strain of identity politics that has been turbocharged by Mr Trump. If Congress fails to decide yet again, then Mr Trump may find himself in the same position as his predecessor, reintroducing something like DACA by executive action.

Better if the lawmakers who spent years denouncing Mr Obama for grabbing power from Congress now choose to exercise that power themselves. The alternative is an act of economic and moral self-harm, in which Congress would further undermine both itself and the standing of the law.