A LinkedIn survey of 500 doctors found 48% supporting single payer, vs. 32% opposed - even though they expected to earn less money. The question was, "Would you support a move to single-payer healthcare, like universal Medicare coverage." The article quotes the doctors to detail some of the horrible paperwork, healthcare, and ethical costs of U.S. medical care now. See Insurance is Driving Physicians Mad; Nearly Half Now Say They’d Prefer Single-Payer.
Also, on wait times for new-patient appointments, see Healthcare Dive (an industry newsletter), http://www.healthcaredive.com/news/americans-wait-an-average-24-days-to-get-a-new-patient-appointment/438531/.