In 1803, the U.S. Supreme Court decided Madison v. Marbury, which established the authority of the court to
declare a law to be unconstitutional, and thus invalid. A basic principle
underlying this authority is that a constitution is on a level superior to a
statute. An entity established in a constitution to interpret it can thus
invalidate a law passed by another body established in the constitution.
Invalidating that other body itself would be an entirely different matter, as
it would involve one constitutional body dissolving another of equivalent
grounding. Accordingly, the constitutional court in Egypt overreached
on June 14, 2012 in declaring the parliament dissolved.
The full essay is at "Egyptian Court Overreached."