evidence: The answer is: just about no one. Every legitimate study ever done on the question shows that voting by noncitizens in state and federal elections is vanishingly rare. That includes the Brennan Center’s own study of 42 jurisdictions in the 2016 general election. We found that election officials in those places, who oversaw the tabulation of 23.5 million votes, referred only an estimated 30 incidents of suspected noncitizen voting for further investigation or prosecution. In other words, even suspected — not proven — noncitizen votes accounted for just 0.0001 percent of the votes cast. But you don’t have to take our word for it: the Cato Institute will also tell you, "Noncitizens don’t illegally vote in detectable numbers." [...] It should come as no surprise then that in the extremely rare instances when a noncitizen does cast a ballot, it’s usually an accident. Sadly, there have been times when noncitizens are misled by mistaken officials into thinking that they’re eligible — and they can face serious consequences even as a result of a mistake. But noncitizen voting is simply not a widespread or even a significant occurrence. And it’s already illegal. We don’t need new laws to stop it from happening. If Congress wants to improve our electoral system, it should focus instead on guaranteeing and protecting the freedom to vote for eligible voters.