There can be no doubt now: The U.S. economy is struggling, inequality is on the rise and too many Americans feel uncertain about their future.

On the campaign trail, I have met many of these men and women, who sit at the kitchen table each week, straining to stretch their dollars from shrinking paychecks. Families who can’t save for retirement with near-zero interest rates. Young parents who are being crushed by their student debt. Shop owners who can’t get a loan because their community bank went out of business.

We’ve...