Not every single American is going to get the virus. Even in a absolute horrific worst case scenario, not even close to half would get Americans. Virus like these just do not work that way and that's part of the reason I get annoyed with doomsday people here and out in life that make it seem that way. Even if the virus was left unchecked and no precautions made, it would likely die out naturally before a third of the American population got infected by it.
To answer you and
RationalOptimist, I think after a month of lockdown across the country, yes, the population would essentially become emotional immune to news of a couple thousand deaths a day especially whens its been communicated that a peak is coming. I've just been around enough situations and people to think I know a good enough about human nature and how willing they are to accept certain things.