I think any immigration bill with a path to citizenship will be written in a way that it takes years and won't be felt in 2016.
Looking at the numbers [1] is interesting though. As far as shifting a state to toss-up status (or past it), it would definitely be big news in Arizona, Georgia, North Carolina, Florida, and Texas.
[1]
http://www.dhs.gov/estimates-unauthorized-immigrant-population-residing-united-states-january-2011A more effective target (via lawsuit?) could be Florida's terrible felony disenfranchisement:
http://fcir.org/2012/08/13/few-felons-regain-right-to-vote-in-florida/http://www.sentencingproject.org/detail/news.cfm?news_id=1334