In Article I Section I of the Constitution it is clear that all legislative powers reside in Congress. The Executive Branch has the responsibility to execute the laws passed by Congess. An Executive Order is not legislation it is a order issued by the President to enforce laws passed by the Congress. While Executive Orders are not mentioned in the Constitution it has been a precedent for a President to issue Executive Orders that he deems to be necessary and proper.
The “Necessary and Proper” clause in the Constitution found in Article I Section 8 was not intended to give Congress and the authority to do whatever they felt was a good idea. This clause meant that they had the authority to pass any legislation that was necessary and proper to implement the powers delegated to the United States in Article I Section 8.
The President is the Chief Administrative Officer of the Executive Branch of Government and has the authority to implement policies and procedures that are neccesary for the administration of the duties and responsibilities that have been assigned to him by the Constitution. Policies and procedures passed by Congress are called laws and effect all of the people. An Executive Order is a policy or procedure issued by the President that is a regulation that applies only to employess of the Executive Branch of government.
Any Executive Order that has any effect on individuals that are not government employees in a violation of Article I Section I. Whenever the President issues and Executive Order that extends to all of the people. Congress has a responsibility to the people to veto any Executive Order that has any effect on non governmental employees.
When a President issues an unconstitutional Executive Order and Congress allows the order to stand they are violating their oath to preserve, protect and defend the Constitution.