In an interesting op-ed in the Washington Post, Jesse Richman and David Earnest of Old Dominion University (my alma mater), say that not only can vote by non-citizens determine election outcomes -- and may very well have done that -- but that current Voter ID laws probably don't offer deterrence.
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.
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-MN) (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. It is also possible that non-citizen votes were responsible for Obama’s 2008 victory in North Carolina. Obama won the state by 14,177 votes, so a turnout by 5.1 percent of North Carolina’s adult non-citizens would have provided this victory margin.
Another of the close elections that Democrats could very well have won based on the votes of illegal voters was NC-07 where Mike McIntire won by 533 votes.
They go on to critique Voter ID laws from the standpoint of efficacy:
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.
With the mishmash of IDs now being issued by states to illegals and to resident aliens, such as drivers licenses, and the general absence of any system to ensure that voters who register are legally allowed to vote, we have created a system where any organization can mobilize sufficient illegal votes to win closely contested elections.
This, as the study hints, is more of an issue with voter registration drives and the ward heeler operations associated with urban Democrat parties:
In 2008, non-citizens with less than a college degree were significantly more likely to cast a validated vote, and no non-citizens with a college degree or higher cast a validated vote. This hints at a link between non-citizen voting and lack of awareness about legal barriers.
While the parties are widely divided on how prevalent vote fraud is, the Democrats take the view that because Eric Holder hasn't investigated it doesn't exist, one would think that both parties would be in agreement that the franchise be limited to those allowed, by law, to vote. The fact that the Democrats will not agree to that point and take any steps to ensure that is the case simply validates what we already knew. In most of the country if Democrats are prevented from cheating they cannot win.