Everyone knows non-citizen voting is super minor, and certainly couldn't alter an election.
Oh wait...
http://www.washingtonpost.com/blogs/monkey-cage/wp/2014/10/24/could-non-citizens-decide-the-november-election/Quote
Our data comes from the Cooperative Congressional Election Study (CCES). Its large number of observations (32,800 in 2008 and 55,400 in 2010) provide sufficient samples of the non-immigrant sub-population, with 339 non-citizen respondents in 2008 and 489 in 2010. For the 2008 CCES, we also attempted to match respondents to voter files so that we could verify whether they actually voted.
How many non-citizens participate in U.S. elections? More than 14 percent of non-citizens in both the 2008 and 2010 samples indicated that they were registered to vote. Furthermore, some of these non-citizens voted. Our best guess, based upon extrapolations from the portion of the sample with a verified vote, is that 6.4 percent of non-citizens voted in 2008 and 2.2 percent of non-citizens voted in 2010.
And as I've contended for years:
Quote
Because non-citizens tended to favor Democrats (Obama won more than 80 percent of the votes of non-citizens in the 2008 CCES sample), we find that this participation was large enough to plausibly account for Democratic victories in a few close elections. Non-citizen votes could have given Senate Democrats the pivotal 60th vote needed to overcome filibusters in order to pass health-care reform and other Obama administration priorities in the 111th Congress. Sen. Al Franken (D-Minn.) won election in 2008 with a victory margin of 312 votes. Votes cast by just 0.65 percent of Minnesota non-citizens could account for this margin.
Yes, the story goes on to note:
Quote
We also find that one of the favorite policies advocated by conservatives to prevent voter fraud appears strikingly ineffective. Nearly three quarters of the non-citizens who indicated they were asked to provide photo identification at the polls claimed to have subsequently voted.
...which is a clear strike against voter ID efficacy, if you exclude the fact that stopping a quarter of them is better than stopping none of them.