On what do you base that assertion?
EOs are enforceable as law unless they are overturned by Congress or the courts.
Because the Constitution's definition of presidential authority is vague, the rules about what can be included in an executive order are unclear. A 1950s Supreme Court decision overturning a Harry Truman executive order offers the sharpest guide to what constitutes a legitimate executive order. The court invalidated the Truman order on the grounds that it attempted to make law. The court further ruled that an executive order is valid only when the president is acting pursuant to an act of Congress or to the Constitution itself. As a result, presidential orders frequently identify the statutes they are relying on.
On what statue would Bush rely?