As much as Joe Biden and many of us on the political left wish this was not the case, the sad fact is that wearing face masks has been politicized in the United States. In fact, the entire COVID-19 pandemic has been politicized in the sense that whether you believe it is happening and how serious it is are closely related to your political orientation. How did we get here? Religious belief certainly seems to have paved the way. After all, believing things that do not reflect reality because they make us feel better is something organized religions have been actively promoting for some time. Still, this tendency to distort reality to conform with our desires probably predates organized religion.
In our modern politically polarized times, it is probably easier and more appealing to many liberals to point the finger at conservative media (e.g., Fox News) and how the Republican Party has devolved since Ronald Reagan. It is easy to understand the appeal of this because it is fairly recent history, and we can pinpoint some of the noteworthy developments. For example, we might point to George W. Bush as an early turning point where our country chose ignorance and mediocracy. Or we might instead point to John McCain's horribly misguided selection of Sarah Palin and insist that this was the moment when everything changed. As tempting as this sort of thing is, I suspect it is too easy. These moments were significant, but I think that is mostly because they reflected how the United States had been changing for some time.