I don't think bias is the right word. It's more that a station not bound by corporate sponsors better has the ability to reflect the voice of the people, and Americans generally lean progressive when you ask them directly about policy.

Most Americans wanting to tax the rich/large corporations: https://www.pewresearch.org/short-reads/2025/03/19/most-amer...

Wanting to legalize marijuana: https://www.pewresearch.org/politics/2024/03/26/most-america...

The government should supply universal healthcare to Americans: https://news.gallup.com/poll/468401/majority-say-gov-ensure-...