Everyone who broke an executive order or law that Obama signed into effect would have a viable constitutional defence in Court, if prosecuted.
However I do not believe the government would immediately revoke Obamas laws and executive orders.Likely the laws would stay in place as the will of Congress and the executive orders would be systematically nullified immediately.
Obama would be impeached if there was time to do so before the end of his term of office. Obama would also bear considerable civil liability from the RNC , and The DNC, not to mention being guilty of a series of electoral crimes.
Likely Obama would be pardoned by the next president ( Joe Biden) just to restore order, but prison would be too good for him , IMHO.
With Trump in the WH, all bets are off. Plus, he said that illegals in prison would be sent back to their own country.