Americans, deliberately, IMO, given less and less news of Europe over the years are not only largely uninformed about its greater safety net and citizen-friendly policies, they also know little of it's negatives, for instance their rising right wing leaders and policies. So no, despite it's appearance, we're not "the only nut on the cake".
http://www.fpif.org/articles/racism_and_recession_in_europeAs you will read at the above link, there's no shortage of right wing, anti-immigrant groups in Europe now, and according to this article, for the last ten years...Just google Right wing Europe and you'll see a plethora of articles. As to your last question, the internet makes good and bad ideas "go viral".
Americans are no more "stupid" than other people and to say so is as bigoted as as throwing that label on any other group. Many are in the grips of Corporations who "play" them and, imo, they may be the most INTENTIONALLY misinformed nation in the western world because of corporate control and a right-wing supreme court.
You have to look at in the context of thirty years of Reaganomics, twenty plus years of propagand radio and diminishing investment in state education...among other things.
During the 1960's, we had the largest middle class in the world and the highest number of college graduates in the world. Since the defeat of Barry Goldwater in '64, the Right Wing has been working steadily to overturn the structures and policies which made that possible.