Some public officials have been sounding the alarm about a type of crime they say goes unpunished and has devastating consequences for American democracy. These officials have proposed laws in recent years to prevent instances of this crime, but their critics have said that those laws are an overreaction to a tiny problem and that the proposed laws do far more harm than what they’re trying to prevent.

Before we talk about the complicated details about this issue, let’s try to understand how prevalent this specific crime — let’s call it X for now — is by comparing it to more commonly discussed violations of the law.

The FBI compiled the statistics on the violent crimes, and in America there are thousands or millions of instances of these crimes per year. But X is so rare that there are no centralized records of it. An expert on the subject found there were at most only 22 “credible cases” of X between 2000 and 2010, and only 9 more from 2010-2014. Virtually all other analyses find similarly miniscule rates of X. But it’s not a violent or high profile type of crime.

So what is X and why are some politicians so worried about it?

We’re talking about in-person voter impersonation — the possibility that someone would vote using the name and voter registration of someone else, or perhaps the identity of a deceased person. It doesn’t sound like a very effective way to cheat an election and, not surprisingly, is therefore almost never attempted.

Of course, politicians are right to want to ensure that elections are fair and equitable, and if there were a massive epidemic of impersonation, a swift response would be appropriate. After all, in today’s often close elections, even a few tenths of percentage points can make a difference to the outcome. But the “problem” of impersonation in elections is so rare as to have almost no effect.

Even if all 31 of the possible instances of voter misrepresentation in the past 15 years were actually criminal attempts to cheat the vote rather than simple clerical errors, and even if they all had occurred together in even the closest national election during that period, they couldn’t have changed the outcome. In fact, there were 1 billion votes cast during that period, meaning in-person voter fraud accounted for at most .000000031 percent of those votes.

To put it another way, comparing the ratio of impersonated votes to real votes is like comparing your running speed to the speed of light.

Well, even if it’s not a big problem, what’s wrong with still trying hard to prevent it?

Most politicians who say they want to crack down on this type of unlawful voting do so by proposing new, strict laws that require people to have certain types of identification — often photo ID — to vote.

In 2014, 31 states had standing laws requiring some form of ID. Many new laws have been added since the U.S. Supreme Court’s 2013 decision in Shelby v. Holder to strike down part of the 1965 Voting Rights Act designed to prevent discriminatory voting laws.

But these laws aren’t harmless. Many people don’t have the right kind of ID already, and getting that ID might be too expensive for some, putting up high practical barriers to people who want to exercise their constitutional right to vote.

A study by a bipartisan government group, the Government Accountability Office, found that 5 to 16 percent of people lacked proper identification depending on the state. It also found that after some states implemented strict voter ID laws, voter turnout decreased as much as two percent or more.

In particular, this type of ID law seem to discriminate against poor people and people from racial minority groups.

From the same study, the direct costs of obtaining the type of ID could range from $14.50 to $58.50, a more significant burden for those of limited means.

In one of the studies considered by the GAO’s analysis, 85 percent of whites versus 81 percent of African-Americans had the correct type of ID. In a study by the Caltech/MIT Voting Technology Project, just 8 percent of white respondents who didn’t vote in the 2008 general election cited having the wrong ID as a “major” or “minor” factor in not doing so, compared to 24 percent of Blacks, 28 percent of Latinos, and 78 percent of Asians.

So what are proponents of voter ID laws really trying to do?

There’s evidence that the people proposing strict voter ID laws have more sinister motives. Almost all those proposing stricter voter ID laws are Republicans, and those people less likely to have proper ID and therefore have a higher bar to voting under such laws tend to lean Democrat.

According to the Caltech/MIT study, almost 16 percent of Democrat non-voters cited having the wrong ID as a “major” or “minor” factor for not voting in the 2008 general election, compared to about 9 percent for Republicans.

More importantly, some of the people in favor of such laws admit their intentions. One Pennsylvania lawmaker said an ID law, later struck down, would allow Republican Mitt Romney to win the state in the 2012 presidential election.

What’s the takeaway?

We should be skeptical of those who use vague fears to pass laws that restrict people’s freedom to vote.

Further reading:

UFO Sightings Are More Common Than Voter Fraud

[Comments: I went into this expecting to do a lot of charts/visualizations/maps, but then realized that a number of the sources I was looking at did a great job with the subject, but these would simply never be seen by people with pre-decided views on the subject. So instead I decided to just link to them in the piece without even mentioning the parts of the issue that could turn people off until I had tried to draw in the reader, and then colorfully convey the extent of the “problem” before going into a more detailed argument about the laws. I can’t really tell if the technique works well or if it comes off as patronizing, so feedback is appreciated. I also made sure to avoid using the term “voter fraud,” because it is politically charged and because voter ID laws are irrelevant to the type of voting fraud that is most common.]