Boris Johnson has been beset by one scandal after another over the years, so why did the latest one bring his resignation? At the New York Times, Martha Gill writes that Johnson made a big political error this week: He apologized. "It was a mistake, and I apologize for it," he said of his decision to appoint a lawmaker to a party post even though the man had been accused of sexual misconduct. Once Johnson said that, ministerial resignations began pouring in. "Offered in the hope of mitigating damage, apologies often instead open the floodgates," writes Gill. "That's not to say politicians are wrong to apologize when they have made a mistake, of course. It's just that, in politics, it tends not to go well." More: