The U.S. has the world's most expensive health care system, but it leaves roughly 30 million people uninsured. As policymakers consider making changes, some are looking to Australia as a model. That nation has achieved universal health coverage at a lower cost, using a successful mix of public and private systems. William Brangham reports for our series The Best Health Care? America and the World. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders