Or, to put it another way: how, practically speaking, can they enforce armed forces who answer to the President to do their bidding instead, like the Law requires them to do?
They may have equal power Legally, aka de jure — that’s what that term means: “de jure” is…
Ahsim Nreiziev

The employees of the Executive branch including law enforcement officers are not beholden to the courts. The “opinion” that the Supreme Court may interpret the “Constitutionality” of an Executive Order is itself extra-Constitutional having it’s origin in Marbury vs Madison. The President is NOT instructed to accept the Supreme Court’s decision anywhere in the Constitution, and does so only out of respect for the institution.

This is High School stuff, maybe consider writing on subjects other than US politics.