"Illegal" is a slur?

I would have thought it was a description. But if it is a slur it is an earned one

"It is rare that a story involving illegal immigration goes by on Fox News or their blog, Fox Nation, without the use of the slur "illegals" to describe undocumented immigrants.

Fox News has chosen to ignore the specific instruction of the Associated Press Style Book, which urges journalists not to shorten the phrase to exclude the word "immigrant," and calls by several news associations to stop using the word because it "pollutes" and can "skew public debate" on immigration.

Source

Posted by John J. Ray (M.A.; Ph.D.).