The U.S. health care system is "unethical" and "politically wrong, morally wrong," former United Nations Secretary-General Ban Ki-moon said in an interview with The Guardian, adding that government officials are beholden to industry interests.

Why it matters: Ban's comments echo the left's growing enthusiasm for "Medicare for All," or something closer to a single-payer system. "Medicare for All" caught on in many Democratic primaries this year and is already shaping up as a defining debate for 2020.