Make the Migrant Protection Protocols Mandatory Act of 2023 This bill requires the Department of Justice (DOJ) to remove certain non-U.S. nationals ( aliens under federal law) from the United States while such an individual's application for admission is pending. Specifically, if such an individual arrived by land from a foreign country bordering the United States and the individual is not clearly and beyond a doubt entitled to admission into the United States, DOJ must return that individual to that bordering foreign country while the individual's application for admission is pending. (Currently, DOJ may choose to detain such an individual or return the individual to the bordering foreign country while the application for admission is pending.)