Words have meaning. The left has done an excellent job of redefining the language in order to win cultural battles, whereas conservatives and libertarians have not. Examples: Pro-choice means killing babies, Marriage equality means redefining marriage to mean something it has never meant, etc. For more excellent examples read The Politics of Deviance by Anne Hendershott.
One that came across my radar the other day was the difference between "immigrant" and "alien". We are constantly inundated with the slogan "people can't be illegal" in reference to illegal immigrants. OK. I concede the point. Instead let's push back on the improper use of the word immigrant.
From the United States government:
Immigrant: An alien who has been granted the right by the USCIS to reside permanently in the United States and to work without restrictions in the United States.
So there's no such thing as an "illegal immigrant" because by definition they haven't been granted permission and so can't be an immigrant at all.
I will now correct people who use the phrase illegal immigrant, making it clear that people who cross our borders illegally and reside here without permission are not, in fact, immigrants of any sort.