It’s time for young Americans to assert their power at the ballot box
David Leonhardt writes: Voter turnout is the biggest opportunity — and biggest challenge — for the new progressive movement. The problem is easy enough to describe: Progressives don’t vote as often as conservatives do. Americans under age 30, for example, lean notably left. They are socially liberal, worried about climate change and in favor of higher taxes on the rich. But most of them don’t vote, especially outside of presidential elections. In the 2014 midterms — when Republicans took control…