He’s never been in favor of it. The only reason he has a leg to stand on in the health care debate is that Obama took a stand and forced him to as part of being VP. Before that Biden was running as the guy who wanted to lower the age of medicare eligibility, and that was the full extent of his health care aspirations. This is when insurance was denying women coverage when they got pregnant, and health care was simply out of reach for the poor so you could die of very treatable medical needs, as if this was a country without resources to do any better.

He toed the line during Obamas terms, and now he’s back to having very limited aspirations-- to nibble around the edge of problems and call it incremental change, but never aspire to take on any bigger changes directly. call it whatever it is, it amounts to the same outcomes: is it how a candidate fleeces the health care companies for donations?, or is it indifference?, or cowardice? In the end its the outcomes that matter with these things, not what a politician says. Words are just air.

Biden says coronavirus’ impact on health system hasn’t changed his mind on single-payer https://www.cnbc.com/2020/03/30/biden-says-coronavirus-hasnt-changed-his-mind-on-single-payer.html

87% of Democrats Support ‘Medicare for All,’ Though Joe Biden Doesn’t https://www.newsweek.com/87-democrats-support-medicare-all-though-joe-biden-doesnt-1522833