A federal court has no jurisdiction. Trump declared an emergency, and that allows him to operate outside the codified law to deal with the emergency. It is not subject to judicial review. The declaration of emergency is literally him declaring he will be operating outside of legal structure as commander in chief.
If he oversteps in exercising his presidential power to deal with the emergency, the Constitutional remedy is that Congress can convene, pass legislation overturning his Emergency. If they do it with 2/3s, they check his move. If he still refuses, they can impeach and remove him.
Judges have no role.
Finally someone who knows what they are talking about. Don’t forget that congress did try that. And they failed. That means that Trump totally has the green light to do what he is doing.
Here is some info on it
https://www.whitehouse.gov/briefings-statements/funds-available-address-national-emergency-border/