A Pew Research Center study compared newspaper language in the period from April 15-29 in 2013 with three other two-week periods—in 1996, 2002 and 2007— when immigration-related legislation was also in the news. It found:
The use of “illegal alien,” a term considered insensitive by many, reached its low point in 2013, dropping to 5% of terms used. It had consistently been in double digits in the other periods studied, peaking at 21% in 2007.
HT: Indiana Law Blog