lower income people. medicare is is not just pop r lar. it's really efficient. instead of a bunch of risk pools, medicare takes all 43 million seniors and puts them into one big giant group where just one enter thety pays the hospitals and doctors and bills. uncle sam. that's the literal division of single payer. one payer pays. medicaid is is like 50 single payers since it's paid for by the federal government and states and the states determine a lot about what it will cover. so whether you live in a drat or republic one might determine whether you get great benefits. now if you think about obama care, the biggest way that the affordable care act expanded the number of people who had a insurance was to put millions of americans on medicaid. during the debate, there was a proposal to allow people to buy into a federal insurance program like medicare, the public option. but thanks to conservatives like joe lieberman, that died.