DR MARC SIEGEL: A Senate candidate's medical title sparks a debate voters shouldn't ignore

There is a long-storied history of physicians as U.S. senators. Sen. John Barrasso is an orthopedic surgeon who previously served as chief of surgery at Wyoming Medical Center. Sen. Bill Cassidy is a gastroenterologist and liver specialist who co-founded a clinic for the poor. Sen. Rand Paul is an ophthalmologist who practiced for almost 20 years. Sen. Roger Marshall is an OB-GYN who delivered more than 5,000 babies. Perhaps most impressive of all was heart surgeon Sen. Bill Frist, who performed