The USA is not the richest country on Earth. I have not check lately but not more than a couple years ago the USA ranked somewhere in the 10th to 20th richest country in the world. Also no, it is not an "American nightmare for a majority of it's citizens." More than half the population is doing very well. The median income is more double the accepted poverty level.

Also you said there are hundreds of thousands of homeless, let's just say there are a million homeless, that is less than a third of one percent of the population. I small number of powerless people are not going to get much action no matter how sad and visible they are.

TEK