Betsy DeVos (right), who has resigned after the US Capitol violence. Photograph: Jim Lo Scalzo/EPA In the 16th century, mice and rats were credited with knowing when a rotten house was on the verge of collapse. This evolved into the idiom about fleeing a sinking ship, but the original version suggested more prescience, an ability to anticipate oblivion and get out ahead of time. The question hovering over the officials quitting the White House is whether they have left it too late, whether they will carry the Donald Trump stain no matter how...