After the assassination attempt on former President Donald Trump last month—in which the bullet missed achieving lethality by less than an inch—Secret Service Director Kimberly Cheatle was called on the carpet by the House Oversight Committee. On July 22, she took full responsibility for the failure to protect Trump, whose ear was nicked by the bullet. In a spasm of self-contradiction, however, she then declared that she would stay on the job “and be responsible to the agency, to this...