Never has there been a presidential race as sprawling and wide-open as the 2020 Democratic primary. It would be a landscape entirely without a map, except that a small handful of battle-hardened veterans have navigated similar terrain before. At the kickoff of the primary debate season four years ago, no fewer than 16 candidates were jockeying for position in the largest Republican presidential field in history—only to end up being mowed down by Donald J. Trump in what became a slaughterhouse of a campaign. What’s in store for this year’s Democrats? To get an insider’s view, POLITICO Magazine invited four...
