On the Democratic National Convention’s second night, Joe Biden’s wife, Jill, took America inside her longtime marriage to the presidential nominee. These things usually strike me as schmaltzy and inauthentic — pre-packaged montages about political leaders and their families, their personal trials and triumphs, their “normal” lives, old photos of first starting out. But as much as we know Joe — indeed, he’s been in public office on and off for the past 50 years — we saw more of the Bidens than ever before. The life they rebuilt after the tragic deaths of Joe’s first wife and daughter, their...