I think generally you must confirm that there was no power grab after the emergency has pasted.
Otherwise you can grab power and refuse to relinquish it after a real emergency that justified the executive powers.
Otherwise you can grab power and refuse to relinquish it after a real emergency that justified the executive powers.
In particular: getting Trump to rescind his border "emergency" will be a long slow process of organizing and accumulating public pressure, whereas there will be an overwhelming amount of public pressure to end the curfew as soon as the power is restored.