Spiro Agnew was Richard Nixon’s Vice President until he was forced to resign after being convicted of tax evasion (a plea deal to avoid more serious charges). My favorite one of his was “nattering nabobs of negativism”.
By my memory, the current conservative victim narrative goes all the way back to the backlash against the civil rights movement and their campaign to take over the southern electorate. They have replaced fact-based, reasoned argument with pejorative labeling ... aka the politics of division. And it’s dominated the national conversation for most of that time. The current violence, both verbal and physical, is exactly what they’ve been working toward for better than half a century. So ... enough with the “silencing” fantasy.
To address your question, confirmation bias is a real thing, this is true. The only remedy I can think of is self-awareness and the conscious decision to seek all the available facts, not just those that support one’s personal position (“welfare queens” anyone?)
You just cannot turf that resposibility to someone else. Do your own homework. So the question of the fact-finder’s bias is one you have to answer for yourself.