WASHINGTON (MarketWatch) — Is America ready for the “S” word?

Vermont Sen. Bernie Sanders, an independent who caucuses with the Democrats in Congress, is the only candidate so far to challenge Hillary Clinton for the 2016 Democratic nomination for president.

Sanders, who is 73 and has been in Congress nearly a quarter century, describes himself as a “democratic socialist.”

“ His message that there is too much concentration of wealth in this country at the expense of greater prosperity for all is certain to resonate. ”

Although Sanders won re-election to the Senate in 2012 with 71% of the vote in his state, it is, to say the least, not politically correct in this country to call yourself any kind of socialist.

John Nichols, a writer for The Nation, titled his 2011 book, “The ‘S’ Word: A Short History of an American Tradition…Socialism,” precisely because, he said, “it is the subject of daily derision, a derision that is at once more intense and more ignorant than at any point in the long history of the United States.”

That is due in no small part to the sharp right turn taken by the Republican Party and the steady stream of right-wing blather on radio and television, where “socialist” is used as shorthand for big government, welfare, high taxes, and any other nefarious policy Rush Limbaugh and his cohorts care to attach to it.

But it is also due to the residue of the long Cold War demonization of communism and the failure of centrally planned economies in the Soviet Union, Eastern Europe, Cuba, and China.

Of course, the Marxism-Leninism of those countries is only one strand of a progressive socialist tradition that also includes social democracy in its various forms, which is still a vital political force in most European countries — most prominently in Scandinavia.

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Comfortable in the conviction that the U.S. is the biggest, strongest economy in the world with the highest standard of living, Americans have for decades tended to sneer at these European countries as inferior, bogged down economically by anti-business policies.

But it is slowly dawning on wide portions of the American public — crushed by stagnant wages, robbed of middle-class jobs by competition with low-wage countries, deprived of health care, burdened by student debt and the astronomical costs of a college education — that this supposed superiority of ours is no longer true, if it ever was.

And that’s just the middle class. The rapidly growing pool of families below the poverty line, forced to work two or three jobs at subsistence wages just to scrape by, is also waking up to the fact that the famous “American dream” is no longer theirs.

George Stephanopoulos, the ABC anchor whose career began as an aide to Democratic presidential candidate Bill Clinton in the 1990s, did a little sneering of his own recently when he interviewed Sanders on “This Week.”

“I can hear the Republican attack ad right now,” Stephanopoulos said after Sanders expounded on the benefits of universal health care, a living wage, free higher education, access to child care, guaranteed pensions and other benefits enjoyed in “socialist” countries. “He wants America to look more like Scandinavia.”

Sanders blinked away his astonishment and replied, “That’s right. That’s right. And what’s wrong with that? What’s wrong when you have more income and wealth equality? What’s wrong when they have a stronger middle class in many ways than we do, a higher minimum wage than we do, and they’re stronger on the environment?”

Even many of Sanders’ fans view his run for the presidency as quixotic — at best a chance to introduce some progressive thinking into the political debate and to push Clinton to the left on certain issues.

But a younger generation of American voters — unmarked by the Cold War and the red scare of the McCarthy era — is much more open to the appeal of socialism and its notion of a solidarity that provides a minimum of financial and social security to every citizen.

In a long article this month for American Prospect, Peter Dreier, a professor of politics at Occidental College, cited a Pew poll finding that young Americans are about equally divided in their attitudes toward socialism and capitalism — with socialism even getting a slight edge.

Some 49% of 18-to-29 year olds had a positive view of socialism, Dreier noted, while 47% had a positive view of capitalism. And only 43% had a negative view of socialism, compared with 47% who were negative on capitalism.

Ultimately, it is the message more than the labels that will catch fire in this campaign. Whether Sanders is labeled a socialist, a democratic socialist, a social democrat, a progressive, a liberal, a populist — or is disparaged by critics as a pinko commie — his message that there is too much concentration of wealth in this country at the expense of greater prosperity for all is certain to resonate.

Citing polls from Pew, Associated Press, Huffington Post and Gallup, Robert Borosage, co-director of the Campaign for America’s Future, said in a blog post last week that this could be Sanders’s moment.

“Sixty percent of Americans agree with him that the ‘economic system unfairly favors the rich,’” Borosage wrote. “Two-thirds of the American public think the rich pay too little in taxes. Two-thirds think CEO pay is too high. Three of four think climate change is a serious or very serious matter.”

In his interview with Stephanopoulos, Sanders says his unusual career in politics should make people wary of underestimating him. The “S” word he has in store for Clinton, the Democrats and the eventual Republican nominee may well be “Surprise!”