Thinking the unthinkable. “I live with a son who is mentally ill. I love my son. But he terrifies me. A few weeks ago, Michael pulled a knife and threatened to kill me and then himself after I asked him to return his overdue library books. … In the wake of another horrific national tragedy, it’s easy to talk about guns. But it’s time to talk about mental illness.” The only problem is talking about mental illness does not advance the left’s political agenda.