Illegal aliens is the official legal term used by members of Congress and the legislation drafted and passed by Congress for the last 50 years!
Illegal alien accurately describes the status of a person that violates US border and Illegal Immigration Law to enter or remain in the United States in violation of those laws.
Many Americans use the term illegal aliens and illegal immigrants interchangeably, but in 2013 the Associated Press mimicked many totalitarian societies by banning the term 'illegal aliens' from their style book. This had a chilling effect on the freedoms of journalists using the term 'illegal aliens' as their articles would be unlikely to be circulated by the Associated Press wire service if they did not comply with this Orwellian edict to destroy the term in news reports!
American citizens, journalists, activists, and candidates should continue to use the term illegal aliens as they like because this is the most accurate description of these types of lawbreakers and it is the accepted language in America's current laws!
Also, the replacement terms of 'illegal immigrants' and 'undocumented immigrants' are very problematic.
Many concerned Americans note that illegal aliens are not 'illegal immigrants' because the term 'immigrants' is a noble and respectable term that should be reserved only for those that legally immigrate to a nation in accordance with the established laws and borders. Illegal aliens are not immigrants, they are trespassers, law violators, and invaders!
Illegal aliens are also seldom 'undocumented'. While the murderous drug and human smuggling cartels instruct their illegal alien clients not to carry documents when sneaking across American borders under cover of darkness, once illegal aliens clear our borders they quickly utilize organized crime networks to establish documents through both document fraud and identity theft.
With US illegal immigration most illegal aliens also engage in document fraud and identity theft both of which are further crimes. Document fraud undermines American jobs, taxpayer resources, and national security while identity theft ruins many American lives and finances.
So illegal aliens are not undocumented, they are carrying around plenty of fraudulent, stolen, and identity theft documents.
Americans that pay close attention to illegal immigration news understand that illegal aliens are people that have no respect for boundaries, America's laws, America, or Americans and their feigned respect is only an attempt to obtain immigration reform amnesty so they can maintain their ill gotten gains!