As recently as February 2020, the Joe Biden campaign was sinking fast

As recently as February 2020, the Joe Biden campaign was sinking fast.  He had finished third in the Iowa caucus and last in New Hampshire primary.  The campaign was unable to raise, money, had secured few high profile endorsements, and there was talk that the campaign would be finished by mid-March.  Bernie Sanders was ahead in delegates and raising huge amounts of money.  Mayor Pete and Elizabeth Warren were climbing in the polls.

As recently as February 2020, the Joe Biden campaign was sinking fast

1)         As recently as February 2020, the Joe Biden campaign was sinking fast.  He had finished third in the Iowa caucus and last in New Hampshire primary.  The campaign was unable to raise, money, had secured few high profile endorsements, and there was talk that the campaign would be finished by mid-March.  Bernie Sanders was ahead in delegates and raising huge amounts of money.  Mayor Pete and Elizabeth Warren were climbing in the polls.  Bloomberg was preparing to spend $1 billion on ads as he jumped into the race.  Biden was doing poorly with young voters, women, and those on the Left.   Everyone seemed to agree that Biden was a flawed candidate who had run a poor campaign.

Yet here we are in late April, and Biden has secured the Democratic nomination.  Firstly, he has now been endorse d by all the other candidates running for the Democratic nomination.  Secondly, he is raising money at record levels.  Thirdly, he is ahead of President Trump by 7 points in recent nationwide polls and by 8 points in the key swing states of Michigan and Pennsylvania.

Given these facts, explain how Joe Biden can run such a bad campaign and still end up in the position he is in today.  In particular, do campaigns really make a difference in who wins if bad campaigns can still win and better run campaigns often lose?