Like both legislative statutes and the regulations promulgated by government agencies, executive orders are subject to judicial review and may be overturned if the orders lack support by statute or the Constitution. Some policy initiatives require approval by the legislative branch, but executive orders have significant influence over the internal affairs of government, deciding how and to what degree legislation will be enforced, dealing with emergencies, waging wars, and in general fine-tuning policy choices in the implementation of broad statutes.

Basis in the United States Constitution

The United States Constitution does not have a provision that explicitly permits the use of executive orders. Article II, Section 1, Clause 1 of the Constitution simply states: "The executive Power shall be vested in a President of the United States of America." Sections 2 and 3 describe the various powers and duties of the president, including "He shall take care that the Laws be faithfully executed".

The U.S. Supreme Court has held that all executive orders from the president of the United States must be supported by the Constitution, whether from a clause granting specific power, or by Congress delegating such to the executive branch. Specifically, such orders must be rooted in Article II of the US Constitution or enacted by the Congress in statutes. Attempts to block such orders have been successful at times, when such orders either exceeded the authority of the president or could be better handled through legislation.

So yeah there is a legal basis