While the SAVE Act makes its way through Congress, it’s important to consider what problem this piece of legislation is trying to address. Republicans claim only to seek better protections against non-citizens voting in elections. But what is the history of non-citizen participation in our elections? Should non-citizens be granted suffrage? And if not, what does that mean about our laws and restrictions regarding access to the ballot?

Far from being radical, allowing resident aliens to vote was once common in America. From 1776 until 1926, 40 US states allowed non-citizen voting at some point for various levels of government, including in national elections. Sentiment changed in the early 20th century. Rising nationalism and xenophobia led states to roll back immigrant suffrage. World War I was a turning point: between 1918 and 1926, nearly every state passed laws revoking the vote from non-citizen residents. And in 1996, the passage of the Illegal Immigration Reform and Immigrant Responsibility Act of 1996 made it illegal for non-citizens to participate in any federal election.

Today, non-citizens residents are still legally allowed to vote in many local elections, including San Francisco, cities in Maryland and Vermont, and even in the nation’s capital.

The historical record provides a guiding principle: people who live and work in a community and pay the taxes that fund it, have a stake in its government. The slogan of the American Revolution was “no taxation without representation”. Its message was clear: anyone taxed should have a say in public affairs. If long-term residents pay taxes (be it income, payroll, sales, property, or otherwise), contribute to the local economy, send their children to local schools, and are generally subject to the laws and regulations of the land, it is undemocratic to bar them from the ballot box. Any legitimate democracy must derive its powers from the consent of the governed. The principle of consensual government is not just “of the citizens”, but from anyone over whom the government exercises its rule, even non-citizen residents. There is no such thing as a privileged democracy. If only a particular noble class, whether that class is defined by wealth, race, sex, nationality, legal status, or citizenship, has a say in government, then the system of governance is an aristocracy.

Even ignoring the above arguments for non-citizen suffrage, it is still true that any just electoral system must be permissive enough to allow some, in fact probably many, non-citizens to vote anyway. William Blackstone, an English jurist from the 1700s, professed: “it is better that ten guilty persons escape than that one innocent suffer.” His formulation (often called the Blackstone ratio) has become a cornerstone of criminal law. It is the reason why our justice system requires juries to be sure beyond a reasonable doubt that a criminal defendant is guilty before any punishment can be doled out. The rational being that no system of evidence or investigation will ever be perfect. Mistakes will happen. But importantly, the error of wrongfully convicting an innocent person is far worse than that of allowing a guilty person to go free.

In statistics, these types of errors are called Type I and Type II errors. In statistical theory, the implications of imperfect tests are considered in a rigorous way. Tests are mathematically designed to strongly favor one type of error over the other (namely Type II over Type I).

Consider the following example. Medical scientists are designing a test for HIV in blood samples. Hospitals need donor blood for blood transfusions. But it’s very important to ensure that the donor blood is free of infectious pathogens, like HIV. A perfect test would predict the presence of HIV in a blood sample correctly 100% of the time. But no such test has yet been (or probably ever could be) designed. Instead, the test will sometimes give false positives (flagging the donor blood as having HIV when it doesn’t) and sometimes false negatives (failing to flag blood that is infected with HIV). Assuming the test has already been optimized to have as few false predictions (both positive and negative) as possible, where should the threshold be placed? To give an equal number of false positives as false negatives? No, clearly giving someone infected blood by mistake is far more dangerous than simply throwing the blood away and using a different sample of non-infected blood. So medical tests are always designed to identify the more harmful of the two types of errors and hedge so that most of the errors are of the least harmful kind.

What does all this mean for voting? Voting is a right not a privilege. By definition, that means it must be granted to anyone who enjoys that right, no matter the cost. In criminal law, the right at stake is liberty. Liberty is a right and must be ensured for all innocent people, or at the very least, we must be so lenient with convictions that we gladly let 10 guilty people walk before robbing an innocent person of their right to liberty. In medicine, doctors take the Hippocratic Oath to do no harm. Which means they must be willing to sometimes waste perfectly viable blood samples if that is required to prevent harming a single patient by injecting them with HIV.

So too must the Blackstone ratio apply to the right to vote. A perfect voting system would allow every eligible voter to freely and easily cast their vote without allowing a single non-eligible voter from doing so. But as with criminal law and medical tests, no such system is achievable. So instead, the system must be designed in such a way as to ensure all eligible voters can exercise their right to vote. For even mistakenly preventing a single voter from exercising their right is a grave harm. And any such system will therefore have to be tolerant enough to allow some non-eligible voters to cast a ballot. Or at the very least, our election regulations should happily allow up to ten non-eligible people to vote before denying that right to just a single person.

How does our current system hold up to Blackstone’s ratio? Estimates put the number of eligible voters in the 2024 presidential election who were denied their right to vote due to suppression, intimidation, or administrative barriers at around 3.5 million. Blackstone’s ratio demands that such an infringement is only justifiable if it were made to prevent 35 million non-citizens from voting! That would constitute almost 70% of the total 52 million immigrants in the US voting! And how many actually voted? The (right-leaning) Heritage Foundation found only 24 instances of non-citizens voting from 2003 to 2023; which seems to suggest a number of less than 24 for the 2024 elections. That’s a factor difference of over a million! And a final Blackstone’s ratio of 1:145,833; as compared to the desired 10:1.

If this kind of crazy lopsided ratio were applied to the previous examples of Type I and Type II errors, it would be the equivalent of imprisoning 145,833 innocent people just to make sure a single guilty person didn’t get acquitted on a technicality. It would mean carelessly injecting 145,833 people with HIV just to make sure a single vial of healthy blood isn’t wasted.

The SAVE Act will only make the number of disenfranchised citizens worse by purging voter rolls more aggressively, instituting a much stricter voter ID policy, and eliminating universal mail-in voting. Instead, we need to do the opposite. We need to eliminate voter ID requirements completely. Even free government IDs are not trivial to obtain and constitute an administrative barrier to many people. We need to mail ballots to every residential address in the country to better accommodate the elderly and people with disabilities. We need at least a week of early in-person voting to accommodate workers. Voting reform should seek to be expansive enough to accommodate those who are unhoused, have no easy proof of residence like a lease or a deed, have no mailbox to receive a ballot, don’t have access to documents like birth certificates, and who have no money to spend on IDs or even transportation. Perhaps we can learn from how our criminal justice system treats access to liberty and presume anyone can vote until the government can prove beyond a reasonable doubt that they are ineligible.

A fair democracy would guarantee the right to vote for all residents and participants of society, citizen or non-citizen. But even if non-citizens are denied this right, a just democracy requires adherence to Blackstone’s formulation. We must redesign our elections to remove barriers and burdens, to cast off the racist scourges of voter suppression and intimidation, to be so zealous in our assurance that all citizens can effortlessly cast their ballots, that in doing so we embrace the reality of many, potentially thousands or millions in observance of Blackstone’s ratio, non-citizen’s casting their votes in every election.