You mean the bubble of persistently hostile coverage, or something that doesn't actually exist?
This sort of coverage is a liability for Democrats because it insulates them from information. A glaring example of this is Elizabeth Warren. It should have been news from the beginning that she had failed to establish personal networks with Black or Latino voters during her tenure as Senator. Her Super Tuesday supporters were 80% white, for an electorate that was only 50% white. When Democrats win elections by turning out Latinos in the southwest and Black people in the south, Warren won just 5-6% of those voters on Super Tuesday, behind Michael Bloomberg.
Elizabeth Warren was a dead-on-arrival candidate because minorities didn’t like her and they’re 40% of the Democratic Party. That should have been a huge story. Instead, the media fawned over her for months because they personally loved Warren. Super Tuesday this blindsided everyone, even though it should have been predictable given what we knew about Warren from the beginning.
If Biden doesn’t run in 2024, expect to see similar fawning coverage of Harris, focused on her “historic” identity and papering over her flaws as a politician. That creates a very real risk that Democrats nominate someone who their own base doesn’t like very much.
The media bubble around Harris is driving Democrats straight to the cliff. Minorities, who make up 40% of the party and are over represented in critical swing states, don’t like her. She was polling at mid-single digits among Black voters in the south (behind Biden, Sanders, and Warren) before she pulled out: https://www.politico.com/news/2019/12/04/kamala-harris-black.... She was polling around the same among Latinos in her home state of California.
Apart from that, she’s a terrible retail politician. When I went to see the candidates speak in Iowa back in 2019, Elizabeth Warren stood around giving everyone hugs and taking selfies after the speeches were over. Harris, meanwhile, quickly retreated to her campaign bus to avoid having to shake hands and talk to people.