The new law makes illegally entering the country a state crime, a misdemeanor. A peace officer, which is broadly defined and can include such people as local police officers and security officers of the state medical board, can inquire about a person’s citizenship and immigrant status if they think they have entered the U.S. illegally. If so, a magistrate can order them out of the country.
It’s unacceptable to the Mexican president to try and stop the current illegal border crossings, because he’s happy to let them pass through as long as their ultimate destination is not Mexico.