It sounds odd, but the scale of Vice President Kamala Harris’ defeat may double as a silver lining. By losing all seven battleground states, suffering their first popular vote loss in two decades and, most importantly, watching President-elect Donald Trump prevail with a working-class coalition that was once their own, Democrats have an opportunity to turn despair into action. Unlike 2016, when they won the popular vote while losing by a sliver in the swing states, or 2020, when they...