Executive orders should not overwrite laws, they can just modify how existing laws should be interpreted if there is a conflict between two laws, or a law and international treaty. Like I said earlier this week, president has authority that others need to respect even if president does something they don't agree with.

In many countries president has right to pardon convicted criminals. As illegal entry to a country is a crime, president has right to block deportation.

Executive orders are in effect until expired (by current president or because of explicit expiration date) or declared against law.