At the beginning of her campaign, she came out swinging. People were vague on her policies, but strong on rejection of Trump and his plans for the country. It was working.
She surged because people were happy that Biden was no longer running. It wasn't specific to her.
And yes, she based her campaign initially on "memes and vibes". As Maya Rudolph's Kamala said: "the lyrics are vague, but the vibe slaps". Coconut trees, being a brat, Republicans are weird.
She should have stuck with it.
You can't build a campaign just on "memes and vibes" long term. And yes, she did fumble the dismount onto a more grounded phase of the campaign.
I do not believe that this is about swaying Republican voters to her side. That is unlikely in any case. What's at issue is how many people are coming to the polls.
It's not just Republicans, although I do think some Republicans are swayable. It is mostly Independents, who are plurality of the electorate.
Like it or not, the Democratic base is not enough to win. And neither is appealing to people like you who on the left even in a place like California.
She needs to win states Hillary lost in 2016 - Pennsylvania, Michigan, Wisconsin. If possible Arizona and Georgia too. Nevada was won by Hillary and also Biden, but is a tossup now. She needs to appeal to voters in these states, not run up the score in NY, IL and CA.