"Over the past five years, Bush has stated that he can defy any statute that conflicts with his interpretation of the Constitution. In many instances, Bush cited his role as head of the executive branch or as commander in chief to justify the exemption.
The statutes that Bush has asserted the right to override include numerous rules and regulations for the military, job protections for whistle-blowers who tell Congress about possible government wrongdoing, affirmative action requirements, and safeguards against political interference in federally funded research.
Bush made the claims in ”signing statements," official documents in which a president lays out his interpretation of a bill for the executive branch, creating guidelines to follow when it implements the law. The statements are filed without fanfare in the federal record, often following ceremonies in which the president made no mention of the objections he was about to raise in the bill, even as he signed it into law." Boston Globe
Before "Marbury vs. Madison" it was not at all clear who had the ultimate "say" on what the Constitution meant in any given situation. In that decision, John Marshall (Chief Justice) effectively asserted the right of the federal courts to interpret the meaning of the Constitution. Before that decision in which the "cause" was an appointment by departing President John Adams of a sheriff in the District of Columbia, the whole thing was "up for grabs."
Adams made a lot of appointments just before midnight on his last day in office and the new Jefferson Administration contested this one. Marbury (the prospective sheriff) sued Madison, the Secretary of State over this and Marshall "found" for Marbury.
Jefferson had previously been of the opinion that the three branches of the federal government were co-equal in judging the meaning of the Constitution. In other words, he had believed that he had just as much right to say what the Constitution meant in any given case as anyone in the federal courts or the Congress.
In this case, he must have been having a bad day, because for some reason he did not ignore Marshall and fire Marbury which he surely believed he could do legally if he wished.
"Everything old is new again." Have at it lawyers.