Reflexively distrustful, eager to make powerful enemies, the young journalist whose Mercedes exploded in Los Angeles one night couldn’t possibly have died accidentally, could he? A t the end of his life, Michael Hastings, like many of the progressive journalists he counted among his friends, felt besieged by an overreaching government. Hastings was living in Los Angeles, and at a Beverly Hills theater in April, he took part in a panel discussion about the documentary War on Whistleblowers: Free Press and the National Security State. Interviewed in May on The Young Turks, a talk show on Current TV, Hastings railed...