The Biden administration refused to explain on Monday why a Parkinson’s disease specialist visited President Joe Biden’s physician earlier this year, one of eight visits to the White House, as the president’s advanced age, 81, continues to be in the spotlight because of his disastrous debate performance. Parkinson’s disease expert Dr. Kevin Cannard visited Biden’s physician, Dr. Kevin O’Connor, in January, one of eight visits Cannard has made over an eight-month period starting...