A prominent advocate of a single-payer national health system will make her case to a presidential commission later today. Dr. Steffie Woolhandler (left, in file photo) of Cambridge Health Alliance and Harvard Medical School is scheduled to testify at 2 p.m. before the President’s Council on Bioethics, which is meeting today and tomorrow in Chicago.... Other experts scheduled to present plans include Len Nichols, director of the health policy program for the New America Foundation, and James Capretta, a fellow at the Ethics and Public Policy Center in Washington, DC... LINK