The key question that a book called "Sex With Presidents" needs to answer is: Whose was biggest? As in: Which president's sexual exploit-filled chapter is the biggest?

The book about our skirtchasers-in-chief has a surprising answer: Franklin Delano Roosevelt has 34 pages devoted to his extracurricular activities, although there's an asterisk since his chapter, "Franklin Delano Roosevelt and the Good-looking Ladies," also spends considerable time on the affairs of First Lady Eleanor Roosevelt.

So it's probably fair to say that the most prolific sex lives in Eleanor Herman's chatty book belong to Warren G. Harding, John F. Kennedy and Donald Trump, each of whom merits 32 tawdry pages.

To be fair about the current occupant of the Oval Office, none of the Stormy Daniels/Miss America anecdotes in "Sex With Presidents" date to his presidency, so the title is inaccurate in his case. Same goes for the chapters on Gary Hart and Alexander Hamilton, both of whom had plenty of sex without the benefit of a presidency.

Because Herman's un-footnoted "Sex With Presidents" is a work of "popular nonfiction," not scholarship, she cuts corners elsewhere, too. Faced with no historical record on what a Hamilton conquest looked like, Herman invents one.

I'm not sure why she declines to call Thomas Jefferson a rapist, since that's what his treatment of underage, enslaved Sally Hemings amounts to. And Herman seems to confirm 15th president James Buchanan's long-rumored homosexuality, for instance, but offers no sourcing other than a chapter where she says her stories about presidents have been well-documented elsewhere.

Sex With Presidents by Eleanor Herman

Herman is correct that many readers will have heard these tales, but she tells them with a gimlet eye and a talent for underscoring absurdity. There is value in collecting them the way Herman has, not just for trivia buffs (if you're ever in a contest where you're required to know that Harding called his penis "Jerry," you're welcome) but also for study of the American presidency.

Herman looks at research into power and hubris and concludes that the link is direct: "Some leaders are successful because they are crazy."

Chapters devoted to 10 presidents who couldn't keep it zipped make that case convincingly, and these are just the ones we know about, including lesser-known horndogs such as Woodrow Wilson and Dwight Eisenhower, whose impotence prevented him from consummating his long relationship with Kay Summersby.

Herman convinces us that a couple elections might have turned out differently if suffrage had been extended to women, who might have cared about Grover Cleveland's rape accusations and Wilson's unfaithfulness to two wives and several mistresses. Smartly, Herman lays part of the blame for our unfaithful presidents at the pens of journalists, nearly all of them men, who agreed to look the other way or flat-out lie about the statesmen they covered right up until they staked out Gary Hart in 1987.

JFK gets the most disturbing chapter — because of sheer numbers, the glee with which he humiliated his wife, Jacqueline, and what we'd now identify as consent issues. His successor, Lyndon Baines Johnson, was an equally prolific cheat, but he's the most sympathetic lout in the book because he actually valued women and had tacit permission from Lady Bird. Oh, and to return to the salacious question of whose was the biggest: According to Herman, it was LBJ.

Chris Hewitt is a Star Tribune feature writer and critic. • 612-673-4367

Sex With Presidents
By: Eleanor Herman.
Publisher: William Morrow, 384 pages, $27.99.