Nick Hanauer, the provocative serial entrepreneur and venture capitalist from Seattle, came by The Wall Street Journal’s Washington bureau this week. Hanauer first drew a lot of attention with a fiery op-ed essay for Bloomberg that made the economic case for raising taxes on the rich and then with a TED talk on the same subject. That talk wasn’t initially posted on the Ted webstie, in part, because TED’s curators deemed it too partisan. After some controversy, stirred in part by Hanauer, the video was posted. Now he’s promoting a book he has written with former Bill Clinton speech writer Eric Liu, a pamphlet of sorts, called “The Gardens of Democracy.”

Hanauer is no Mitt Romney venture capitalist. That’s for sure. His basic argument is that businesses don’t create jobs, consumers do. Or, more precisely, that the economy is an ecosystem in which businesses and their rich owners thrive only if there is a large middle class with enough money to buy their goods. And he sees today’s widening inequality and pressure on the middle class as a threat to prosperity. In his case, this isn’t so much about fairness, but about sustainability.

His describes the conventional wisdom this way: “If you pour money into rich people, like an ingredient, in the form of lower tax rates, jobs will squirt out of them…which makes people like me job creators.” He thinks that’s nuts.

“Lots of grass will equal lots of zebras, and lots of zebras will create a great situation for the lion. But the opposite is not true. More lions won’t create more zebras. And more zebras won’t create more grass.” Current economic policies, he says, “have made it cozy for the lions.”