In her new book “Morning After the Revolution: Dispatches From the Wrong Side of History,” Nellie Bowles, a former New York Times journalist grown disillusioned with both the mainstream media and the left, writes about the year 2020, when the combustible confluence of the pandemic, the murder of George Floyd and the prospect of Donald Trump’s re-election made politics and culture go “berserk.” She describes a liberal intelligentsia “wild with rage and optimism,” brimming with “fresh ideas from...