T he Trump administration is by its own account devoted to stamping out obesity, cancer, and many other chronic diseases in America. But its public-health officials are also attuned to a very different sort of threat: a faulty cast of mind. “ Groupthink is the fundamental problem,” said National Institutes of Health Director Jay Bhattacharya in May. The nation’s scientific institutions have become hidebound. According to Bhattacharya, Health Secretary Robert F. Kennedy Jr., and other top