WASHINGTON — American democracy has been thoroughly eulogized in recent years, written of with grief and nostalgia in numerous best-selling books. Law professor Ganesh Sitaraman has also taken up the subject, but his has a more aspirational title: “The Great Democracy.”

“I’m particularly excited to talk about this book because I’ve been thinking about it for 20 years,” Mr. Sitaraman said at an event celebrating the book in Washington last month. “Which I know seems crazy because I don’t look that old.”

Mr. Sitaraman is, in fact, not that old. He is 37, which is old enough to run for president. Like his close friend and Harvard classmate Pete Buttigieg, the former mayor of South Bend, Ind., is doing.

“The Great Democracy” makes the case for expansive democratic reform — it’s a time for transformation, Mr. Sitaraman writes, not a return to some old normal. And the ideas in the book are getting decent airtime on the 2020 campaign trail. Mr. Buttigieg is wrestling with the notion of democratic reform through his own campaign; and Mr. Sitaraman now serves as a senior adviser to Senator Elizabeth Warren of Massachusetts, a mentor since Harvard Law School.