Dr. Robert Zarr, Physicians for a National Health Program. Any day now – Vermont Senator Bernie Sanders will introduce a bill to create a single-payer healthcare system right here in the United States. Progressives have tried to pass single-payer before, but this time feels different. With Obamacare popular but flawed – and with Republicans exposed as scam artists – the idea that we should guarantee healthcare for all Americans resonates now more than ever. Which raises the question – what IS single-payer healthcare?