Sign up for the Slatest to get the most insightful analysis, criticism, and advice out there, delivered to your inbox daily. Even before Donald Trump’s improbable victory in 2016, political observers of all stripes have confidently predicted that it was all about to come crashing down. It happened after the release of the Access Hollywood tape, when dozens of Republican elected officials rescinded their support over Trump’s comments bragging about grabbing women’s genitals. The end was again nigh in May 2017, when former CBS anchor Dan Rather declared that “the curtain may be coming down on this act of this...