He was just 24, but speechwriter David Litt had already become President Barack Obama’s go-to guy for anything considered “kishke-related.” In Litt’s parlance, that meant he wrote the president’s speeches aiming to connect with Jewish Americans on a gut level — things like holiday and anniversary commemorations, but not, say, Israel or foreign policy. That explains Litt’s presence one Friday night in the White House library in April 2012. A jet-lagged Obama had just returned from a trip to Asia and the last thing on his schedule was to record a video greeting for Passover. “All right,” Obama said grumpily...