The majority of Americans are not Muslim radicals
Not even fundamentalist Christian preachers in America screech "Infidels!" as often as Middle Eastern imams, publicly announcing their desire to kill them or convert them all. But you know this. You know which group uses the term "infidel" the most often, but again, you rush in with some contrarian and inane remark, seeming to miss the point or misstate the case deliberately.
To make this really simple, NO, atheists are not considered, called and condemned as "infidels" by the majority of Americans who are moderate Christians.