In his excellent book, Words that Work, Dr. Frank Luntz goes into detail to explain how words create mental images that results in a positive or negative preception of an issue. It is critically important to carefully choose the words we use in debate.

The fanatic left has known this for a long time.

Whenever the situatio allows we should carefully state that illegal aliens (the hard left's "undocumented immigrants") are in fact "citizens of a foreign power who have crashed into our home, evade arrest and refuse to leave." When you say it that way illegal aliens don't seem to be so harmless or little people worthy of pity do they?

May I suggest that it would be useful to use the term "illegal alien squaters," in addition to "illegal invaders."