The coronavirus highlights many of our vulnerabilities, including the system we use to get food from the farm to the table.  Lately, the pandemic has forced U.S. farmers to face the unthinkable. They plowed under perfectly good vegetables when schools and restaurants shut down and their market vanished. Livestock producers have euthanized hogs and chickens. They couldn’t get the meat to consumers when workers got sick and packing plants closed. The growing season also brings migrant workers to U.S. farms. They come for jobs they need. But this year, some come wearing face masks, worried they may take the virus home to their families.