The racket inside Donald Trump’s head must sound like the roar of a train. Investigations are coming at him from all sides — from the special counsel, from the U.S. attorney in Manhattan, from the New York state attorney general, from the relentless poking around of news organizations and, soon, from the hydra-headed investigations of a newly Democratic House of Representatives. And he knows that as he inevitably weakens, the appearance of weakness will encourage others to pile on — the injured and the outraged, the mistreated and the merely insulted — and they will materialize with their meretricious lawyers and they will take him down, lawsuit by lawsuit, investigation by investigation, until he writhes on the floor, an ending as squalid as his administration.