More than ever, we need mandatory national service

On Nov. 6, the day after the presidential election, I asked a group of my students why Donald Trump won. "Because so many people hate people like us," one of them replied.

He wasn't wrong. The best predictor of how you planned to vote was whether you possessed a college degree. People who haven't graduated from college represent the majority of Americans, and they backed Trump by large margins. As Trump famously quipped, he loves the uneducated. And they love him back.

They...