This should not be news. But in today’s febrile world of Twitter-fed headlines, it bears repeating: there are two old people running for president. One is a 68-year-old woman whose legs gave way in the late summer heat on Sunday. Hillary Clinton has also coughed a few times on camera. Both events have taken on cosmic significance in this otherwise sedate and stately presidential contest. Four years ago, Clinton fainted and banged her head while sick with a stomach virus. Her doctor detailed last year the handful of pills she takes regularly: for her allergies, thyroid, and blood thinning. These facts have driven the conservative media into the kind of hysteria that requires its own medical attention.