Perhaps the single most important issue facing voters this fall is also the issue that most desperately cries out for a historical account: Who will be allowed to vote, and under what conditions?

Democratic politicians have been making regular use of history in their attacks on the rash of new laws that make it harder to vote, limit early and absentee voting, and purge existing voters from rolls. They have evoked Jim Crow, segregation, and poll taxes with both direct and indirect comparisons.

As they should. The right to vote is deeply tied to its own contextualized history, and the Voting Rights Act of 1965 appropriately relies on histories of discrimination to establish covered jurisdictions. And yet, while we applaud the use of history in policy formulation and debate, the public discourse on this issue raises important questions about how historians, journalists, and politicians evaluate the nature of truth and how the past can best be analyzed for constructive analogy.

This is nowhere more evident than in the determinations of PolitiFact, a Tampa Bay Times fact-checking project which strives "to help you find the truth in American politics" by measuring the accuracy of politicians' statements with its trademarked "Truth-o-Meter." Among the finalists in PolitiFact's 2011 competition for "lie of the year," was a reference by Democratic National Committee Chair Debbie Wasserman Schultz to Republicans who "want to literally drag us all the way back to Jim Crow laws" by enacting new barriers to registration and voting. Earlier that year, PolitiFact Georgia had taken to task a mayoral candidate for making an analogous comparison between a crackdown on undocumented workers and the infamous "black codes." More recently, PolitiFact Florida called U.S. Rep. Alcee Hastings's reference to poll taxes "half true." Fact or fiction?

Each time, PolitiFact editors called on historians to help them judge. Each time, PolitiFact's analysis and resulting verdicts demonstrated how, in this useful conversation between heated political rhetoric and detached journalistic analysis, historical thinking finds its place at the table to be as uncomfortable as it is essential.

Asked about Wasserman Schultz's reference to a "literal" return to Jim Crow (a statement she quickly walked back), historian Glenda Gilmore (Yale Univ.) pointed out, "Historians of the South use the term 'Jim Crow laws' to mean discouraging voting in a way that impacts minority voters. So, I think that she was exactly right in her use of the phrase." Jane Dailey (Univ. of Chicago) similarly took a broad view, noting that "Groups interested in limiting political competition have always justified suffrage restrictions as necessary checks on election fraud. Like today's GOP, turn-of-the-century southern Democrats argued that poll taxes and literacy tests would reduce fraud at the polls."

Setting aside these evaluations by distinguished historians, PolitiFact rated Wasserman Schultz's statement "False." "Although there are some similarities in the two sets of laws," PolitiFact wrote, "they are outweighed both by the differences between them and by the inflammatory nature of the phrase, which all but calls the laws' supporters racists." But it is probably more accurate to observe that Wasserman Schultz has committed the misdemeanor of exaggeration rather than the more egregious offense of inaccuracy.

This is not "literally" Jim Crow; perhaps not even figuratively Jim Crow. But it is like Jim Crow. Perhaps "akin" would be a good term here: the legislation (as Dailey insightfully suggests) uses the same logic as late 19th-century disenfranchisement, mobilizing unproven allegations of voter fraud to blatantly disenfranchise particular voters, even if not at the same magnitude as the earlier period. Current efforts are not the resurrection of Jim Crow; they are the descendants of Jim Crow. The DNA can be traced, its family traditions apparent.

PolitiFact reentered the debate a few months ago when U.S. Rep. Alcee Hastings (D-Fla.) labeled Florida's requirement that some residents prove citizenship (and pay for their own postage) a "backdoor poll tax." PolitiFact editors went further into the matter than ever before, gathering comments from 14 scholars and even consulting parts of a book and an article.

PolitiFact's staff assembled and relayed a considerable range of views by historians on the poll tax in the United States. Alex Keyssar (Harvard Univ.) took the broad comparative view: "Any effort to introduce an election procedure that requires some voters to incur financial costs could be thought of as a metaphoric or perhaps real poll tax." T. Adams Upchurch (East Georgia Coll.) disagreed, and the PolitiFact editors ended up largely convinced by his emphasis on a significant difference between the new Florida requirements and the 19th-century poll tax—affordability. The 19th-century poor who were faced with prohibitively high poll taxes, Upchurch noted, truly could not afford to vote, and "could absolutely and rightly claim discrimination.... But a stamp? Please."

Hence PolitiFact's assessment of Hastings's statement as "half true." This is probably just about right, even if the rating fails to capture all of the issues involved. Keyssar argues that as a matter of principle, this is indeed a poll tax, and the actual amount can be considered a slippery slope. But a stamp is, after all, only a stamp. The question could perhaps better be addressed by exploring intent: once again, was the intent to make it harder to vote? Would some people predictably find it harder than others? Sometimes historians are better at identifying the right question than at providing a short answer fit for the "true/false" section of a test.

And perhaps this is the issue. PolitiFact admirably works to educate the public on the accuracy of politicians' references to the past. Sometimes this is a straightforward task; often it is not. PolitiFact generally seeks to confirm or disprove one-for-one correspondences between the present and the past. The historians cited by PolitiFact appear more willing to allow for comprehensive thinking; recognize that categories like "Jim Crow" aren't cut-and-dried; and accept the idea that intent matters. Historians, less attached to the tyranny of the Truth-o-Meter™, are likely to engage questions by explaining issues of continuity and change, and greatly enlarging the context. Though PolitiFact has made a concerted effort to include historians in its analysis, the Truth-o-Meter™ might not be readily calibrated to measure their responses.

A better approach was on exhibit over the summer at the Washington Post's Plum Line blog, where Jonathan Bernstein wrote about the voting issue and used history in a way that acknowledged the complexity of the history of voting, spoke broadly about the issue instead of restricting conversation to the most dramatic examples, and avoided the "history repeating itself" trap. He wrote:

Some textbook treatments of the franchise in U.S. history treat voting as a gradual but sustained series of victories…. That story is wrong.

A more accurate version of the story is that plenty of people who once had the vote then lost it. The most dramatic example of this is African Americans in the post-reconstruction South. But there are plenty of other examples…. We may be in the process of undergoing a similar restriction right now; indeed, that's probably one of the key things at stake in the next few election cycles.

Bernstein understands what appears to elude both the politicians and the fact-checkers. The franchise in the United States (as elsewhere) has ebbed and flowed, with restrictions rising and falling for citizens on the basis of such categories as gender, race, and property ownership. One-for-one comparisons between then and now are generally less meaningful or helpful than the questions generated by an exploration of the circumstances of these changes. It is imperative, however, to understand that we never truly eliminated discriminatory disenfranchisement. Its kin, its DNA, are still part of the body politic, and we need to think carefully, and historically, about each and every attempt to limit the right to vote.

James Grossman is the executive director of the AHA.

Allen Mikaelian is the associate editor of Perspectives on History and coordinator of media relations for the AHA.

This column was adapted from recent posts by the authors at AHA Today, the blog of the American Historical Association.