Currently the plan to peel off left wing voters seems to be not by doing concessions on policy but by giving Biden a more left wing profile than his voting record would show. Mostly by doing uh, stories I guess (the thing about his dad being okay with gay people and how he got arrested in south africa, both hard to call "truth" by any measure).
Seems like his handlers have no idea that this does not bear fruit vs a left wing that only moves when they see actual material change and not just aesthetics.