I have read the Peter Schweizer book “Clinton Cash: The Untold Story of How and Why Foreign Governments and Businesses Helped Make Bill and Hillary Rich.” It is something. Because it is heavily researched and reported and soberly analyzed, it is a highly effective takedown. Because its tone is modest—Mr. Schweizer doesn’t pretend to more than he has, or take wild interpretive leaps—it is believable.

By the end I was certain of two things. A formal investigation, from Congress or the Justice Department, is needed to determine if Hillary Clinton’s State Department functioned, at least to some degree and in some cases, as a pay-for-play operation and whether the Clinton Foundation has functioned, at least in part, as a kind of high-class philanthropic slush fund.

I wonder if any aspirant for the presidency except Hillary Clinton could survive such a book. I suspect she can because the Clintons are unique in the annals of American politics: They are protected from charges of corruption by their reputation for corruption. It’s not news anymore. They’re like . . . Bonnie and Clyde go on a spree, hold up a bunch of banks, it causes a sensation, there’s a trial, and they’re acquitted. They walk out of the courthouse, get in a car, rob a bank, get hauled in, complain they’re being picked on—“Why are you always following us?”—and again, not guilty. They rob the next bank and no one cares. “That’s just Bonnie and Clyde doing what Bonnie and Clyde do. No one else cares, why should I?”

Mr. Schweizer announces upfront that he cannot prove wrongdoing, only patterns of behavior. There is no memo that says, “To all staff: If we deal this week with any issues regarding Country A, I want you to know country A just gave my husband $750,000 for a speech, so give them what they want.” Even if Mrs. Clinton hadn’t destroyed her emails, no such memo would be found. (Though patterns, dates and dynamics might be discerned.)

Mr. Schweizer writes of “the flow of tens of millions of dollars to the Clinton Foundation . . . from foreign governments, corporations, and financiers.” It is illegal for foreign nationals to give to U.S. political campaigns, but foreign money, given as donations to the Clinton Foundation or speaking fees, comes in huge amounts: “No one has even come close in recent years to enriching themselves on the scale of the Clintons while they or a spouse continued to serve in public office.” The speaking fees Bill commands are “enormous and unprecedented,” as high as $750,000 a speech. On occasion they have been paid by nations or entities that had “matters of importance sitting on Hillary’s desk” when she was at State.