The Democratic Party is a big, sprawling mess, and has long been that way. In the Trump era, it spans the ideological distance from Bernie Sanders to Cindy McCain. There is no one Democratic “base”: Jim Clyburn’s socially conservative voters are part of that base as much as, or more than, Elizabeth Warren’s ultra-progressives are. Democratic coalitions are typically assembled by highly targeted benefits rather than mobilized by big messages as Republicans often are: $35 insulin, defense of abortion rights, student-loan forgiveness, environmental measures. The current coalition includes intense supporters and intense critics of the state of Israel. Altogether, not an easy horse to ride. The best rider is one who is able to keep reminding each part of the coalition that it needs to get along with the other parts.