Dan Cohen sat across the table from a former classmate who had spent years antagonizing him when they were growing up together and playing baseball. The classmate had something he wanted to get off his chest. “He was newly sober and just apologizing for just being mean to me,” Cohen recalled of the conversation, which occurred around 2011. At the time, Cohen said “it meant a lot” because he thought the man sitting across from him had changed his ways. Now, he’s not so sure. That former classmate, Cohen said, was Max Miller, the embattled Ohio Republican congressman whose reelection...