Judging from last week’s debate, Democrats running for President see America as a Dickensian nightmare of inequality. It’s the best of times for millionaires and billionaires, and the worst of times for everybody else. Time to wake up from the Barack Obama economy, folks, and admit how many more Americans are prospering from the faster economic growth and tighter labor market after the policy changes of 2017.

“Who is this economy really working for? It’s doing great for a thinner and thinner slice at the top,” Massachusetts...