Biden supported a 1994 crime bill that is considered racist today.
Some context is required there, though. The 1994 crime bill did have significant support among Black leaders and activists. It was seen as an imperfect solution to a critical issue that disproportionately affected Black neighborhoods at the time.
If you look at Hillary’s broader statements, she has always favored universal single-payer healthcare. She worked her ass off to get a plan passed in 1994, and she was relentlessly attacked for it.
The last time Democrats got successful movement on healthcare was March 2010 with a filibuster proof Democratic majority in the Senate, a majority in the House, and a popular new president in the White House. Even then, only a relatively tepid compromise bill was passed, with even the “public option” stripped out (thanks Joe Lieberman).
Will conditions change in the future? Quite possibly, especially as our health care becomes increasingly unaffordable. Maybe it’s not so helpful to have senior politicians telling voters something is impossible and potentially affecting the Overton Window. But Hillary’s warning, that Bernie Sanders’ plan hadn’t a chance of getting passed, was a good reality check.