When Bill de Blasio won the New York City mayoral election with 73 percent of the vote, I couldn’t help but wonder whether it was the start of something big. For more than two decades it has been taken as an article of faith that New York City voters prefer social liberals who will nonetheless protect the interests of wealthy Manhattanites. But throughout the campaign, de Blasio focused relentlessly on the city’s problems with economic inequality. He proposed raising taxes on high earners to pay for universal pre-K education. He promised to force luxury real estate developers to build affordable housing. He…