There were 56 illegal votes in the 10 years between 2001 and 2011.

http://www.politifact.com/punditfact/statements/2016/nov/18/blog-posting/no-3-million-undocumented-immigrants-did-not-vote-/

The Republicans use ID laws to deter blacks from voting. It is similar to a  strategy they used to prevent black votes for a hundred years, till the 1965 Civil Rights Act.