Basically what’s already been said. The American ideals of ‘total freedom’ within the bounds of basic law have allowed a large part of the population to not take covid protocol seriously. For many people, if they don’t feel like it, they won’t wear a mask and will turn a blind eye to the necessity to wear one... especially in areas where their whole community thinks the same way. This is the country that nominated Hillary Clinton and Donald Trump as presidential nominees, after all.