there were decades of record immigration but that has leveled off and even seemed to start reversing itself. From Pew Research Center.
There were 11.3 million unauthorized immigrants in the U.S. in 2014. The population has remained essentially stable for five years, and currently makes up 3.5% of the nation's population. The number of unauthorized immigrants peaked in 2007 at 12.2 million, when this group was 4% of the U.S. population.
2Mexican Unauthorized Immigrant Population Declines Since 2007 Peak Mexicans make up about half of all unauthorized immigrants (49%), though their numbers have been declining in recent years. There were 5.6 million Mexican unauthorized immigrants living in the U.S. in 2014, down from 6.4 million in 2009, according to preliminary Pew Research Center estimates.