Othering
With these tweets, former President Donald Trump is attempting to use language to separate Mexican immigrants from Americans. These tweets come from when Donald Trump was trying to secure the Republican presidential nomination and later when Trump was attempting to get Congress to allocate the funding to build the border wall at the southern border.
By referring to Mexican immigrants as "illegals", Donald Trump is criminalizing the person rather than the behavior or action they took part of. Immigrating to the country undocumented is one of the only instances where the individual has been criminalized instead of the individual commiting an illegal act. Some may argue that this is due to the racial component that is often present with immigration. Calling Mexican immigrants as "illegals" creates a divide between Americans and immigrants, with Americans being viewed as "lawful" and Mexican immigrants as inherently "bad" or "criminal". Further, by putting the conversation of "illegal" immigration back into the national spotlight, Trump has indirectly brought the racial stereotypes of Mexicans back into mainstream media since immigration policies and attitudes impact the perception of Mexican Americans and immigrants. Additionally, the usage of the word "invasion" implies that the immigrants are unwelcome and unwanted in the United States.