In almost every period of our history, the national focus has been on the future. The country in recent weeks has been engaged in three unusual debates, focused not on a misty future but on a cloudy past. Here are the old questions, full of new implications, which are being asked by policymakers and voters alike:-- How did we get into this irrational situation with medical care, where health insurance is tied to employment?No one designing a health-care system for a post-industrial nation of enormous wealth and with some of the most advanced medical facilities in the world would tie the health of its citizens to the employment of its citizens.