Federal courts enjoy the sole power to interpret the law, determine the constitutionality of the law, and apply it to individual cases. The courts, like Congress, can compel the production of evidence and testimony through the use of a subpoena.
The federal courts' most important power is that of judicial review, the authority to interpret the Constitution. When federal judges rule that laws or government actions violate the spirit of the Constitution, they profoundly shape public policy.
