Here is what I tell people who ask why I keep writing about so many crooked politicians.

Shortly before I left the Atlanta Constitution, where I was the political editor, an Atlanta alderman was indicted for something or other. It was front-page news, of course.

Then, shortly after I joined the Chicago Sun-Times, a Chicago alderman was indicted for something or other. And it didn’t even make the front page!

I went up to my editor and asked, “Are aldermen getting indicted routine news around here?” He just glowered at the stupidity of the question.

So as a political writer, more or less by default, I covered many stories about boodle and clout (wonderful Chicago words).

In time, I wrote five books about political corruption—and efforts at reform—in Chicago, the state of Illinois, and the U.S. Congress. Some of the people in those stories were outsized characters who seemingly could have been made up by a novelist.

Speaking of novelistic characters—a famous novelist once told me that he threw away a serious nonfiction manuscript and wrote it up as a novel instead. Why? “Because people will believe fiction much more readily than they will believe nonfiction.”

That observation inspired me to write a novel to bring to life the grifters, grafters, cheaters, prosecutors, reformers, and even innocent people caught up in scandals whom I had encountered. I found their counterparts in some characters, both real and made up by me, in the early years of Prohibition under President Warren G. Harding.

I found that the times, the early 1920s, revealed in Stumbling in the Public Square were much like our own: contempt for the law, illegal government spying on citizens, sex scandals, foreign wars . . .