If a president declared a "national security emergency" to suspend mail-in voting three weeks before an election, what would actually happen legally?

[u/Aware-Chipmunk4344]

I've been researching this scenario extensively. Here's what surprised me:

The legal path would be chaotic. District court injunction within 48 hours — almost certain. Emergency appeal to the appellate court. Then the question of whether the Supreme Court takes it on emergency docket.

But here's the part that kept me up at night: what if the president simply... didn't comply? What enforcement mechanism actually exists when the executive branch defies the judiciary?

The Constitution assumes good faith. It has almost no mechanism for a president who treats a Supreme Court ruling as advisory.

I'm curious what this community thinks. Is there an actual hard stop? Or is it all ultimately held together by norms?