Chris Beneke is associate professor of history at Bentley University and the author of Beyond Toleration: The Religious Origins of American Pluralism. Randall Stephens is reader in American Studies and history at Northumbria University and the author (with Karl Giberson) of The Anointed: Evangelical Truth in a Secular Age.

Earlier this month, George Mason University's History News Network asked readers to vote for the least credible history book in print. The top pick was David Barton's right-wing reimagining of our third president, Jefferson's Lies: Exposing the Myths You've Always Believed about Thomas Jefferson. But just nine votes behind was the late Howard Zinn's left-wing epic, A People's History of the United States. Bad history, it turns out, transcends political divides.

If these books seem an unlikely pair, they also have a good deal in common. Both flatter their readers by promising to let them in on hidden truths of which most people, and most experts, are unaware. Both offer stark, simplistic accounts (buttressed, in Barton's case, by a litany of historical errors). And both undermine the notion that the past can be rationally interrogated, debated, and revised by people from opposite sides of the ideological spectrum.

The History News Network no doubt intended to amuse as much as edify: it made no pretensions to random sampling and didn't specify what "credible" history might involve. But there's a graver implication: If a poll were conducted to identify the most influential popular historians of the past three decades, Barton and Zinn might also rank at the top. Both have attracted large and powerful followings. Barton's Christian nation narratives are revered by the likes of Glenn Beck, Mike Huckabee, and Michelle Bachmann, while Zinn's unforgiving indictments of capitalism and American nationalism made him a patron saint among many progressives and won him the admiration of celebrities such as Matt Damon and Bruce Springsteen....