If this president can create a new legal status for aliens unlawfully present under the terms of the Immigration Act, future presidents will have the same authority to employ broad notions of “prosecutorial discretion” to gut the enforcement of whichever laws they dislike—using the excuse that “Congress has failed to act.”

The supporters of DAPA may well rue the day that presidents seized this kind of extralegal authority. Whatever immigration policy any of us may favor—and I, for one, would like to see major reform—we should all be able to agree that the executive branch must follow the law until it has been amended by Congress.

The district court order is a preliminary injunction, meaning that it isn’t the final word in the case. The court expressly declined to base its decision on constitutional grounds or even on substantive administrative law grounds, but solely on the Obama administration’s failure to go through proper procedures. That doesn’t make the decision any less significant. It means that the administration cannot implement its unilateral DAPA program unless and until the decision is reversed on appeal by the Fifth Circuit Court of Appeals or by the Supreme Court. It will not be easy for the administration’s lawyers to persuade those courts that Judge Hanen got the law wrong.