Is "Illegal Immigrant" A Slur?

I thought that THIS opinion piece on CNN by Charles Garcia headlined, "Why 'illegal immigrant is a slur," was interesting both for what it said and what it didn't say.

"When you label someone an 'illegal alien' or 'illegal immigrant' or just plain 'illegal,' you are effectively saying the individual, as opposed to the actions the person has taken, is unlawful. The terms imply the very existence of an unauthorized migrant in America is criminal... Migrant workers residing unlawfully in the U.S. are not -- and never have been -- criminals. They are subject to deportation, through a civil administrative procedure that differs from criminal prosecution..."

Some of this is semantics.  But there is power in words, and I thought this assertion was thought-provoking.

Charles Garcia continues, "Another misconception is that the vast majority of migrant workers currently out of status sneak across our southern border in the middle of the night."

I suspect that many people would read this sentence with a lot less emphasis on the carefully placed phrase 'in the middle of the night,' however, if they were aware that, according to THIS 2010 Pew Research Center study, "At the national level, 58% of unauthorized immigrants are Mexicans... In seven states, they make up 80% or more of the unauthorized immigrant population... Among children with at least one unauthorized immigrant parent, 70% have parents from Mexico, 17% from other Latin American countries."