[gammateam]

The federal courts can create law solely because overruling them is nigh impossible. The Supreme Court exists to rule on constitutional matters, but it is merely the final arbiter and uses that to its advantage based on case law they made for themselves.

Overruling the Supreme Court requires a constitutional amendment and this won't happen, and the court rarely does something untenable or an impossible outcome for a functioning society as it wants compliance. It tries to match a partial collective conscious understanding of a topic.

When it does act as fill-in legislature, Congress/Legislatures are capable of simply changing the law it ruled on, such as repealing the legal framework supporting enforcement agency.

The courts can also overrule itself in a future court case.

(The Supreme Court exists by the constitution, the other federal courts are created by congress and have a path to the supreme court.)