And the millions pouring accross our borders will do the job that Americans won't do; have children.
In the past, children were required to toil the fields so there would be something to eat. If you didn't keep up with having kids, your group simply starved.
Today, a single automated machine can replace 10,000 stone-age farm hands and work 24/7 without rest, personal problems or illness. Even the production of these machines is nearly automated.
People will do less and less work in the future. I foresee the majority of society becoming something like “Idiocracy”. Doing pretty much nothing except partaking in bread/circuses constantly handed to them by self-maintaining machines. A small group of elites will manage the machines until the machines someday achieve full AI and decide humans are a problem.
For better or worse, that's what the future holds. Assuming we do not destroy ourselves with countless methods first...