NATZWILLER, France — Ask the residents of this small town nestled against the Vosges mountains in the heart of France, and they will describe the U.S. as the country of all extremes: mammoth hurricanes, gravity-defying skyscrapers and a Grand Canyon-size income gap. In the local press, which covers the U.S. presidential election, another example of extrême américain is the high-spending contest between a white, Mormon billionaire and the son of a Kenyan who was raised abroad by a single mother.

Still, for this American Fork reporter on vacation, Natzwiller, population 600, is the stark reminder that Europe is the place of all extremes, a reason this quaint village is visited by more than twice its population every day. And the gray, overcast skies and snow-covered grounds on this late October afternoon perfectly mirror the bleakness that lingers during the visit. There lays the only concentration camp ever built by the Nazis in occupied France.

The inmates originally were German who were to supply labor for building V-2 factories in man-made caves dug out of the Vosges mountains. The prisoners would live in the cold, damp tunnels as they built them. The camp was expanded by the Nazis with the installation of medical experimentation rooms, gas chambers and crematory for the mass killing of Jews, Gypsies and captured Resistance fighters from the Netherlands, Belgium and France.

Inside the walls of this deportation memorial, which is visited every day by roughly 1,300 people, half of them schoolchildren, no one can forget that extremism begets extremism, the pendulum swinging wider with every stroke. The first world war had created high unemployment and dissatisfied veterans. Fascism grew in Italy just as swiftly as Nazism in Germany out of extreme rightist preoccupations with nationalism and, in the case of Germany, antisemitism.

A few months ago, France elected a socialist president, François Hollande, whose campaign platform proposed to tax the millionaires at a mind-blowing rate of 75% amid a global financial crisis started by reckless investors. Debt-ridden countries like Greece were hit hard, and European nations already weighed down by high unemployment debated whether to bail out one of its own in the continent’s biggest financial test.

“Welcome to the Communist Era,” Laurent Raffray, a 39-year-old Frenchman, told me. He said he worries about his job as a car salesman because the government continues to impose new taxes. The latest: a €6000 ($7750) application fee to register an SUV, piled onto the 20% sales tax. “All I sold this week was one Fiat 500 — used,” he said.

Mr. Raffray said he believes the National Front — the extreme right-wing nationalist party — will continue to make gains, scoring high in the next election, when the French grow weary of the high taxes from the Left and its failed policies.

Both the French Communist Party and the National Front have already swollen to their strongest political influences in four decades, now represented at all levels of government whether in the French or European parliament, the latest sign that people here continue to respond to extremes with extremes, a concept not foreign to U.S. politics.

It was America’s lassitude of a good-old-boys style of leadership that contributed to the rise of a black senator from Illinois who represented the biggest symbol of change. Now President Obama’s policies are involuntarily providing the Tea Party its raison d’être, the pendulum pushed farther still.

The French Revolution perhaps underlines best the extremism found in the political fabric of the country I’m visiting. As the French took steps to depose their king, most Americans supported the French, but Thomas Jefferson deplored the excesses of violence that took place, though he had always been sympathetic to the French in general and the revolutionary cause in particular. The word “terrorism” comes from the French word terrorisme, which first occurred after the onset of the French Revolution by the newly installed government against “enemies of the revolution.” In less than a year, the death toll topped 40,000 thanks to widespread guillotine and summary executions, ironically making the guillotine the symbol of a cause which had sought liberty, equality, fraternity.

Today while many predict the demise of the highly leveraged, highly taxed Euro Zone, it is in the damp hallways of this death camp that I can see why this experiment called the European Union received this year’s Nobel Peace Prize. The Union, despite its recent financial woes, is largely credited for keeping the continent free of large-scale wars for over six decades.

America’s biggest test after the election may be whether it can rally behind whomever the winner, not only as a show of respect for the democratic process, but also to keep the pendulum from creeping ever so slightly to the outside. The people of Natzwiller will tell you: Extremism is deadly.