Over at Dissenting Justice, Law prof Darren Hutchinson points out reasons that the DC Circuit might reverse Judge Leon without reaching the merits of the Fourth Amendment question he decided. According to Hutchinson:
[T]he Supreme Court is very reluctant to enjoin policies related to national security. This is so, even if the defendant has violated the letter of the law. National security could provide a basis to reverse the injunction.
In Winter v. National Resources Defense Council, the Supreme Court reversed a preliminary injunction granted to halt certain naval training operations offshore in California. The plaintiffs argued that the operations could harm protected species of aquatic animals. More importantly, a federal statute literally required the military to submit an environmental impact statement before conducting the activities, but the government did not submit such a statement. Accordingly, the military violated an unambiguous statutory provision.
Despite the fact that the government violated the statute, the Court held that the preliminary injunction was improper. The Court reasoned that it could not second-guess the military on national security concerns (and that it was not clear that the activities would irreparably harm, if at all, any aquatic species). So, national security weighed against issuance of the injunction despite plaintiffs proving actual success on the merits.
The circuit court and the Supreme Court would likely apply similar logic in this case. Rather than delving into the constitutional questions — which courts wish to avoid if possible — the appeals court could reverse on the grounds that the opinion does not give enough weight to national security concerns.
Furthermore, [Judge Leon's] opinion does not even contain a section that “balances the equities” by weighing the harm to the plaintiffs in the absence of the injunction against the harm to the defendant if the injunction is affirmed. This, however, is a mandatory part of the test.
The procedural dimensions of this case provide ample room for reversal — without examination of the constitutional questions.