Executive Order. Congress has allowed them to substitute for Congressional legislation. They will.
Executive orders cannot countermand what is already in the US Code. You will not see “law # 300” is repealed by executive order.
If so attempted, we have all we need to impeach. Law is NOT made by the executive branch. War can be apparently.
Push comes to shove, House can refuse to initiate funding for any act created whole cloth.
What might be possible is a obamacare like “deemed to have passed”. In which case there will be armed insurrection fairly certain— for which the executive maoist is trying to develop a federal police force like an occupying army ignoring posse comitatus (since it isn’t the Army really!!).
This is of concern certainly.