The chair of the president’s reelection campaign, Jen O’Malley Dillon, is a legend in her business. Born in Boston and educated at Tufts—where she majored in political science, and, way more important, was the captain of the softball team—J.O.D. got her start in presidential politics on Al Gore’s 2000 campaign, where she quickly built her reputation as one of the great field organizers of her or any generation. From there, she ascended the ziggurat of Democratic operatives methodically, skillfully, without a slip: from Iowa field director and Iowa state director for John Edwards in 2004 and 2008, respectively; to battleground state director and deputy campaign manager for Barack Obama in 2008 and 2012, respectively; then chair of the D.N.C. Unity Reform Commission after the 2016 election, and campaign manager for Beto O’Rourke’s much-hyped but short-lived primary bid in 2020.