When STAT first compared projected U.S. deaths from Covid-19, in early April, there seemed to be a glimmer of good news: A prominent model had just lowered its estimate for total deaths through Aug. 4 from about 100,000 to 60,000, reflecting the apparent success of three weeks of social distancing across much of the country. On Wednesday, April 29, the country blew past 60,000, more than three months before the Institute for Health Metrics and Evaluation projected. (The 60,000 almost certainly undercounts Covid-19 deaths, by about 9,000.) IHME, whose model has been criticized by many epidemiologists, now says the most...