Proponents of these laws argue they are necessary to combat what they say is potentially widespread voter fraud. “As an eligible citizen, you must be … guaranteed that your vote is not stolen or diluted by thieves and fraudsters,” the Heritage Foundation, a conservative policy organization, ominously warns on its web site.Heading its list of recommendations to combat this fraud is a voter ID requirement. Yet, among the 292 voter fraud convictions between 1998-2015 that the Heritage Foundation lists in its self-described voter fraud database, only four actually involved in-person voter impersonation, with far more involving false registrations committed by public officials or political operatives. The Heritage Foundation declined to respond to multiple requests for an interview.

“The kind of fraud that voter ID laws would resolve is … vanishingly rare,” said Myrna Pérez, deputy director of the Voting Rights and Elections Project at the Brennan Center for Justice. In 2007 the Brennan Center released a comprehensive study on voter fraud, which concluded: “It is more likely that an individual will be struck by lightning than that he will impersonate another voter at the polls.” The study’s author Justin Levitt is a Loyola Law professor currently serving as Deputy Assistant Attorney General in the Justice Department’s Civil Rights Division. In a follow-up examination of voter fraud allegations between 2000-2014 Levitt found just 31 credible allegations nationwide of in-person voter impersonation out of more than 1 billion ballots cast.

Levitt isn’t the only one who’s failed to find any widespread fraud that a voter ID would prevent. In an ongoing federal lawsuit (Veasey v. Abbott) brought against Texas’ voter ID law, court documents show that by a state Attorney General official’s own admission, in the 10 years before the Texas voting ID law was passed, “only two cases of in-person voter impersonation fraud were prosecuted to a conviction.” A total of 20 million votes were cast during this period.

Kansas Secretary of State Kris Kobach has been a highly visible proponent of voter ID laws, and in July 2015 convinced the Republican-dominated state legislature to grant him the power to prosecute voter fraud, making him the only secretary of state in the nation with such authority. So far Kobach has found only six cases to prosecute for voter fraud occurring in elections dating back to 2010.

In March 2015, Ohio Secretary of State Jon Husted, after launching an investigation into voting fraud going all the way back to 2000, announced that of the state’s 7.7 million registered voters his office found 145 individuals who weren’t citizens and that 44 of them had voted in an election.

With an electorate of 153 million voters no one doubts that instances of improper voting are somewhere above zero. Yet the gulf between evidence of voter fraud and the Republican-led push for stricter voting laws is staggering. Critics of voter ID laws argue that they offer no meaningful protection against fraud.

“When voter fraud occurs it should be taken very seriously … and we should have the mechanisms to make sure that it doesn’t happen,” said Pérez. “But cases where people are in a position to exploit the system are much more common than some random person pretending to be someone else.” An analysis of election fraud by the journalism studies program News21 found that more than half of all fraud convictions between 2000 and 2012 involved either election officials, campaign workers or voting registration organizations. Just 1 in 207 fraud accusations involved voter impersonation, the only type of fraud that voter ID laws prevent. “If [voter ID advocates] were really concerned about fraud there’s a bunch of other things they could do,” Perez added “Our voting machines are vulnerable. We’re asking people to vote on machines that are the equivalent of old-school flip phones. Our registration rolls are a mess.”

Voting rights advocates say that what voter ID laws are really good at is making it more difficult for a particular subset of Americans to vote; primarily low-income black and Latino citizens — groups who tend to vote for Democratic candidates. The relative lack of academic data on voter suppression can make it a difficult argument to prove or dismiss. Voter ID proponents, for example, often point to studies showing an increase in black voter turnout in some states after voter ID laws took effect, while opponents highlight studies in other states that show the opposite result. Pérez finds turnout to be an inherently flawed metric.

“Turnout is a conglomeration of a bunch of different individuals” she said, noting that you could have 600 people blocked from voting but if you also had 601 new voters in the election the turnout would show an increase. “It’s very imprecise and will lead to bad data and conclusions for somebody to look at statewide turnout numbers as the dispositive measure of disenfranchisement. Instead one should look at whether there are concrete impacts on specific people and specific groups of people.”

In 2014 the U.S. Government Accountability Office surveyed 10 independent studies measuring how many citizens possess the types of IDs most commonly required by state voter ID laws. While the studies show an overwhelming majority of registered and/or eligible voters do have such IDs, in five states that enforce voter ID laws an average of 8 percent fewer black and Latino registered voters have valid IDs compared to their white counterparts.

For many of these eligible voters, getting a valid ID is not a simple process. “For one, those without a driver’s license don’t have a car,” said Kathleen Unger, president of VoteRiders, a non-profit group that helps voters obtain valid IDs. “So they’re not able to just drive down to the DMV to get a license.” And while states do offer the option of a free voter ID card Unger says, “In many cases there can be a cost associated with getting a ‘free ID’. Obtaining a copy of a birth certificate or a change of name document not only costs money but requires a trip to another agency. With these laws there are so many people who just won’t vote.”