On a recent WhoWhatWhy podcast, I spoke with Princeton historian Julian Zelizer who offers a provocative argument from his new book In Defense of Partisanship. At a time when nearly a third of Americans view both major parties with disgust and many blame partisan loyalty for our democratic decay, Zelizer says that strong, disciplined political parties — not feel-good Biden-style bipartisanship — have historically been crucial to America’s greatest achievements.

The problem isn’t that parties fight hard for their beliefs; it’s that we’ve lost the guardrails that once transformed partisan combat into incremental but lasting progress.