And then there were ten. Democratic candidates on stage, that is

The darkness led by the GOP. You can’t implement anything better than what we have while the people in power are pushing for something far worse than the status quo.

Biden’s strategy on health care, however one feels about the plan itself compared to something more NHS-like, is politically appealing:
(1) People like the ACA. (They do!)
(2) I, Joe Biden, was instrumental in getting ACA passed. (He was! Though after he opposed it internally…)
(3) The GOP wants to tear down ACA. (They do!)
(4) So let’s associate me, Joe Biden, with something Americans love, and the GOP with something they hate.

It is a completely reasonable political stand for Joe Biden to take, and because of (2) he can get more mileage out of it than can, say, Kamala Harris.

Any improvement on the plan needs to come through the legislature, so let’s win the damn Senate this year. If a MFA candidate wind the White House, they can send a MFA bill to the legislature and twist their arms to pass it. If Biden wins the White House, the Senate can pass such a measure and send it up for Biden to sign (which he probably would, whatever he’s saying now). If Trump wins the White House, political purists can feel self-righteously happy about not having had to compromise while the country continues to go down in flames.