Want a preview of the next great debate dividing progressives? (Or if we are lucky, uniting them.)

We need to stress jobs and income, right? The average voter knows that the economy is doing well—on average—but life prospects are still lousy for regular people, especially young people, especially young people without well-off parents and a family welfare state.

What to do? Well, in the first ring of the progressive circus we have Guaranteed Jobs, a favorite among some progressive advocates: The government guarantees a job at a decent wage for anyone who needs and wants one.

Sounds great. In fact, this is a little tricky. We had some experience with it in the 1970s, under Jimmy Carter. One of the slippery questions is the relationship of temporary public service jobs to regular civil service jobs.

In the next ring of the circus, we have Universal Basic Income. Also tricky. Yes, we need to supplement work-derived incomes. But the impact of robots is exaggerated. There could be plenty of work to go around; the challenge is to create more meaningful jobs that pay well—starting with a base pay of at least $15 an hour for all human service jobs, and a lot more of them.

And then we have a Massive Infrastructure and Green Transition Program. Or, as I like to say, World War II without the war. We didn’t need make-work jobs or income subsidies during the war, because there were more jobs than people, and they paid well.

Basically, we need all three approaches, but for me anyway, the centerpiece is the infrastructure program. It’s a very good debate to have—as long as the protagonists don’t turn on one another.

Could that happen? Democrats divided against Democrats?

Old joke: What do you call three lefties in a room? Answer: a split.