Two ideological camps are in a bitter struggle over voter identification rules. The issue receives an airing in the Supreme Court this week. Neither side in the voter ID dispute has a lot of facts behind its arguments, but the quarrel is not likely to end soon. Proponents of liberty should beware of one thing: If a national voter ID requirement takes hold, such a system would be cause for regret across the ideological spectrum.

It has become an article of faith among many Republicans and conservatives that voter fraud is a significant problem or at least a significant threat. “Voter fraud” is what occurs when ineligible people vote or eligible people vote in more than one jurisdiction. This is distinct from “election fraud,” where the counting or reporting of votes is corrupted in any number of other ways. Voter fraud, the conservative camp believes, skews elections in favor of liberals and Democrats.

Liberals and Democrats believe just as firmly that efforts to secure voting processes more tightly, such as voter ID requirements, seek to suppress the vote of their traditional constituencies. They believe that toughened voter ID laws will skew elections in favor of Republicans and conservatives.

This dispute is unlikely to recede. Political animals will hold the hotly contested 2000 presidential election as their strongest election memory for a generation. Modern electioneering processes will increasingly heat the debate as well. Information‐​driven campaign techniques — sophisticated polling, “micro‐​targeted” messaging and get‐​out‐​the‐​vote efforts — will allow the political parties to tune their campaigns more finely, seeking tighter victories so they can use resources more efficiently. This increases the chance that small irregularities including voter fraud could affect outcomes.

A couple of broader policy efforts also stoke these fires. Increasing voter participation has been a policy fetish for the last decade or two‐​never mind whether more voting for its own sake makes a better democracy. The “Motor Voter” law, passed in 1993, has pushed voter registration materials at new and re‐​registering drivers, with dubious results, including increased chances of voter fraud. (It is an unfortunate practice, using driver licensing bureaus for mission‐​creepy purposes.)

The growth in absentee balloting has undone some of the protections against voter impersonation and multiple voting that previously existed. People are much more reticent to commit fraud in person‐​it’s riskier‐​so in‐​person voting was a natural security against impersonation fraud. Voting in multiple jurisdictions is simply too time‐​consuming to do on any scale when it has to be done in person.

There have been registration frauds‐​canvassers in big electioneering pushes have signed up anyone and everyone, for example, the living and the dead. But proven instances of people going into polling places unqualified to vote, masquerading as others, or in multiple jurisdictions‐​these have been few and far between. As Loyola Law School professor Richard Hasen points out, a lot of attention is being paid to voting irregularities. Absentee ballot fraud and vote‐​buying schemes have been found, while impersonation voter fraud has not. Impersonation fraud on any scale is as hard to conceal‐​it requires a lot of coordination. The strong inference is that there is not much of it happening.

Were there evidence of routine or systematic voter fraud, it might be appropriate to establish systematic measures to counter it. As in all policy decisions, the steps taken to counter occasional voter fraud or the threat of it must be balanced against their costs.

The state of Indiana instituted a strong voter ID requirement in 2005. In the Crawford v. Marion County Election Board case being argued before the Supreme Court this week, the ACLU and NAACP claim that Indiana’s voter ID requirement will disenfranchise the poor and the elderly. On the margin, it probably will, but none of the parties in the case are people who have actually been dissuaded or prevented from voting. The case might be better left to ripen until an individual can claim that he or she was disenfranchised by the law. If that happens, the logic and consequences of the Indiana law should be put under rigorous scrutiny.

But another concern with voter ID is the registration and tracking system that might be dreamt up to implement it. In 2005, the Commission on Federal Election Reform (known as the “Carter‐​Baker Commission”) issued a report finding “no evidence of extensive fraud in U.S. elections or of multiple voting,” though it sometimes does occur and could affect a close election. To inspire confidence in the system, the commission recommended using the national ID card created by the REAL ID Act as a voter registration card. (Learning more about REAL ID, at least one member of the commission backed away from that recommendation.)

A national registration system for voting would quickly be repurposed and used for many other kinds of regulatory control. There is no shortage of proposals for national registration and control of citizens. Should the voter ID tempest in a teapot boil over, the tiny specter of voter fraud could thrust a mandatory national ID into the hands of law‐​abiding citizens.

The Constitution gives Congress power to regulate the elections that select its members and, to a lesser degree, the president. But Congress does not have to use that power to its fullest extent. States recognize their own interests in fair elections, and they should experiment among themselves with ways to secure elections while making sure the vote is available to all qualified people.

There will never be a “perfect” voting process. Striking the balance between security and access involves tradeoffs. Top‐​down attempts to perfect voting processes could be quite damaging to Americans’ liberties.

The qualifications to vote are typically residency in the relevant jurisdiction, attainment of a certain age, sufficient mental capacity, and absence of a felony conviction. These credentials can be proven without identity cards and databases, or with tightly minimized documentation and recordkeeping. To ensure that American voters enjoy their franchise in a free country, clumsy voter ID rules should be avoided. A national voter ID system should be taken off the table entirely.