Michael Kazin’s latest book is American Dreamers: How the Left Changed a Nation. He teaches history at Georgetown University and is co-editor of Dissent.

The makers of historical documentaries seldom seek to challenge the received opinions of their audiences. Even the most talented filmmakers tend to exalt the already exalted and shovel dirt on the thankfully deceased. One can, one should be moved by a production like Freedom Riders, which PBS aired this summer on the fiftieth anniversary of that dramatic, violent episode in the civil rights saga. But Freedom Riders comforts more than it educates and fails to ask such tough questions as why the notion of black and white people sitting together in a bus station could ever have provoked such rage.

So there is something fresh, even rather brave, about “A Nation of Drunkards,” the opening ninety-minute episode of Prohibition, the three-part film by Ken Burns and Lynn Novick, which premieres on public television on October 2. For most Americans—and, I would bet, nearly anyone who chooses to spend a Sunday evening watching a documentary on PBS—the century-long movement that first limited and then banned the manufacture and sale of alcohol appears either hopelessly quaint or quaintly sinister. To explain why and how the prohibitionists were able to amend the Constitution requires an empathy for Christian moralism that does not come easily to secular liberals—a cohort to which the filmmakers (and, I imagine, most New Republic readers) happily belong. Burns and Novick dramatize this moralism well. But that is not the only virtue of their film; whether intentionally or not, the documentary also suggests a way to think about the fortunes of the right-to-life movement, the prohibitionists of our own time....

The right-to-life movement has not existed for a century, as did the dry army, but four decades after Roe v. Wade, its influence is formidable. Nearly every Republican office-holder and many a Democrat opposes abortion, and few physicians in red states will serve a woman who wants one. In many ways, the prohibition movement was the precursor to the anti-abortion battle. Right-to-lifers also view themselves as crusaders for both Christ and the family, most are avid church-goers and get backing from the pulpit, and they have the numbers and resources to keep battling into the distant future. Like the Anti-Saloon League, they have also followed a careful, state-by-state strategy of cutting off opportunities for engaging in what they view as sinful behavior.

As the history of prohibition instructs, the surest way to defeat the right-to-life movement would be to make abortion illegal. Not solely because it would give the movement what it wants, but also because a firm majority of Americans still support the right to choose in all or most circumstances—just as a majority back in the 1920s probably thought it was all right to buy a drink (the polling business did not yet exist). A reversal of Roe (much less a “pro-life” amendment) would quickly make heroes and heroines out of health workers who violated the law—much as this film, and most histories of the period, glamorize tipsy flappers and gangsters wielding submachine guns. The long history of prohibition unmistakably demonstrates that a divided public will quickly turn hostile when protestors with decent motives elect officials who carry out indecent assaults on individual freedom. In America, a movement of moralists is never so vulnerable as when it succeeds.