It was not about overcoming the political establishment in South Carolina. It was about stopping Biden by having a close second place by Bernie. Bernie could have had a stronger second place showing in South Carolina. Instead, he had a weak performance and Biden had a smashing win. It changed the psychology of the entire race just a few days before Super Tuesday.

If Sanders had been able to blunt Joe's victory in South Carolina, it possibly would have meant Bernie would have done much, much better than he did on Super Tuesday. Bernie was heavily favored in Super Tuesday prior to Biden's big win in South Carolina.

So it was not about winning the state or overcoming the political establishment there. Rather, it was about having a stronger second place showing and preventing Biden from having a massive victory. Instead, that is what happened. Joe had a major victory, and it propelled him to success on Super Tuesday.