I don't think so... Bernie's never won the democratic nomination because he is seen as a socialist/too left. Idk what the strat should be but maybe not that.

But the Democrats leaned to the conservative side. They had Bernie Sanders winning all the party votes and by using dirty tricks they kicked him away and switched to Hilary Clinton. Because she represented a much more conservative side. Ever since the Democrats leaned further to the conservative side. doing what the Reps did before they went insane and followed Trump. There is now not a single party promoting social aspects in the US. Trump calls out the "radical left" but it is a shallow term without meaning, there is no group promoting "left" ideas.

They don't need to radicalize at all, if they did the least bit of shifting their policy to the left, they could have beaten Trump easily, but they decided to move right and campaign with Bush-era war criminals trying to get the votes of people who hate Kamala, this strategy worked spectacularly well for Hillary Clinton in 2016