A leading advocacy group for single-payer healthcare meanwhile is criticizing Obama’s proposal requiring Americans to purchase health insurance. Physicians for a National Health Program says the latest census figures show the mandate approach has failed in Massachusetts, where it became law in 2006. At least 352,000 Massachusetts residents, or 5.5 percent, were uninsured last year. The group’s co-founder, Dr. Steffie Woolhandler, said, “Today’s numbers show that plans that require people to buy private insurance don’t work. Obama’s plan to replicate Massachusetts’ reform nationally risks failure on a massive scale.”