Why Democrats should be cautious about public banking

Earlier this month, California passed a bill allowing 10 city governments in the state to establish a public bank. It's only the second state in the U.S. to take the leap — North Dakota has had a public bank for a century — but other states are dabbling in the idea.

In the aftermath of the 2008 financial collapse, when the privately-owned banks of Wall Street are as bloated and vulnerable to crisis as ever, public banking seems like an idea whose time has come: It's being proposed for everything...