Which isn’t to say “These Truths” is an update of “A People’s History of the United States,” Howard Zinn’s radically revisionist book from 1980. Yes, Lepore pays heed to Frederick Douglass and Cesar Chavez and the African-American lawyer and civil rights activist Pauli Murray, among others. But her book is less about a struggle between heroes and villains than it is about the country’s often tortured approach to political equality and natural rights — truths that were supposed to be self-evident but have been treated as if they were anything but.

“I’ve told a story,” she says simply. “I’ve tried to tell it fairly.”

One part of this story is how the founders — and generations of politicians thereafter — contorted themselves and their reasoning to maintain a concept of equality that excluded women and people of color. Recounting how such jarring discrepancies would play out in the founders’ actual lives, Lepore is matter-of-fact. James Madison almost sold a slave to buy a book of enlightenment philosophy. Despite George Washington’s ambivalence as a slaveholder, the people he claimed as his property were still subject to a crude and brutal utility: His dentures were constructed out of a combination of ivory and nine teeth yanked from their mouths.

Few, if any, politicians come out of Lepore’s account looking pristine, though she casts some as more calculating and opportunistic than others. A vengeful Richard Nixon thrives on “innuendo and smear”; Ronald Reagan’s charisma “oozes out of the screen.”

Nixon and Reagan are depicted as creatures tied to a more cynical, more fractured version of the truth, one no longer beholden to the founders’ emphasis on facts and evidence (no matter how selectively applied). And Lepore doesn’t let liberals off the hook. Contemporary politics, in her telling, has become a degraded battleground of competing sensitivities: By the 1980s, she writes, the left and right had both adopted “a politics and a cultural style animated by indictment and indignation.”

Lepore is at her most formidable when she’s marshaling historical evidence. Some of her more literary flourishes read like good intentions gone awry. Slavery, she writes, in a passage both woolly and wooden, “had poisoned a people and nation. It had turned hearts to stone. It had made eyes blind. It had left gaping wounds and terrible scars.” Recalling 9/11, she says that a couple who jumped from one of the upper floors of the World Trade Center “looked like paper dolls.”

It’s perhaps an indication of the severity of our current predicament that Lepore, for all her deep understanding of the American experience, feels it necessary to end “These Truths” with a wistful, heartening epilogue that pictures the republic as a beleaguered ship. “It would fall to a new generation of Americans, reckoning what their forebears had wrought, to fathom the depths of the doom-black sea,” she writes. “They would need to drive home nails with the untiring swing of mighty arms and, with needles held tenderly in nimble fingers, stitch new sails out of the rugged canvas of their goodwill.”

This is too pretty by half. After so many pages of cold, hard truths, the last thing I wanted was to have them warmed over. To feel cheated by such platitudes is a testament to how good the rest of the book is. This cleareyed history had done its civic duty: It primed me to miss the Lepore who tells it like it is.