Mass Migration Law and Legal Definition

According to 8 USCS § 1182, [Title 8. Aliens And Nationality; Chapter 12. Immigration And Nationality; Immigration, Admission Qualifications For Aliens; Travel Control Of Citizens And Aliens], the term 'mass migration' means a migration of undocumented aliens that is of such magnitude and duration that it poses a threat to the national security of the United States, as determined by the President.