What, exactly, do you base this on? As a person of color who spent most of her life in a blue state and the last 10 years in a red state, my observation is that both sides (whether or not they’re on the fringe) are living in echo chambers.
I suspect that politically-motivated media is largely to blame, reinforcing our biases and our personal interpretations of the truth. One need only look to the recent backpedaling on the origins of COVID-19 to see how this has played out. The lab leak theory that was once seen as a conspiracy embraced by the radial right is now proving to be a more-than-likely possibility (and even the most likely possibility, according to former CDC Diretor Robert Redfield). Those who felt entitled to believe the virus was born in a Wuhan wet market have seen their version of truth upended, yet they don’t make the obvious connection: perhaps truth is becoming increasingly obscured from all of us in an era of rampant politicization of issues on all levels, from science to the economy to geopolitics.
Progressives by no means have a monopoly on the truth. Ironically, your statement is illustrative of the myopia you are highlighting.